Define computer terminologies
Computer: This is an electronic device that accepts data, process, store, retrieve and gives out information.
Data: This is a raw fact of a given subject e.g. (1+1, a+b, a²)
Information: It is the data which has been processed or end result obtained after process.
Bit: This is the smallest unit of information a computer can process.
A bit is a dot(.)
Byte: It’s a collection of 8bits.
A byte can be a character A, B,2,8 etc.
Electronic device: It’s a machine which requires power to operate.
Process: state of converting data into information.
Retrieve: make the data available when needed/recover information stored.
2.FACTORS TO CONSIDER WHEN BUYING A COMPUTER.
· Cost
· Size of memory egg 256mb,512mb,1gb,2gb
· Speed of the processor egg P1, P2, P3, P4 GHZ
· CD-ROM, DVD ROM.
· Quality and Durability upgradability Technology wise, period system can last.
3.ADVANTAGES AND DISADVANTAGES OF A COMPUTER
i. Advantages of a computer
1. Stores large amount of information in a limited space.
2. Speed-performs task very fast compared to man effort
3. Consistency-gives the same result given the same instructions
4. Secrecy-Information is fairly protected if the computer system is well managed(password)
5. Versatility-can do the same thing over and over again without getting worn-out
6. Computer can work under hostile environment egg Volcanic eruptions.
ii. Disadvantages of a computer
1. They are expensive to acquire and maintain
2. Need expertise, which is expensive to hire and maintain
3. Computers are health hazards i.e., Eye problems
4. They cut down employment opportunities to those not skilled.
5. Can lead to lose of information if not well managed.
4. EXAMPLE OF FIELDS WHERE COMPUTERS ARE USED.
Industry and commerce.
Keeping track of orders and bills transactions in companies and industries
Used in defining new products or services and to carry day to day operations
communication sectors.
Digital communication worldwide is done through computers, unlike analogue communication using the telephoning systems
E-mail communication
Electronic file transfer where communication is done through internet.
Education and Reference
Computers incorporates database that are useful in managing education resources.
Internet provides reference materials for learning
Computer systems are used in libraries for storage of information and retrieval.
Entertainment sectors
Computers support high quality pictures which are stored in communication worldwide etc.
Computers support music files using high speed and efficient digital storage devices such as DVDs, CDs etc.
Games are also supported by computers as a source of entertainment at homes and other special places.
Health care and Medicine.
Keep patient records and medical Insurance data
Computers perform medical diagnosis.
Used in monitoring patient at I.C.U(Intensive Care Unit).
Police and Defense
Computer are nowadays used greatly in fighting crimes through computer forensic
Police are able to enter fingerprints to database which are automatically analyzed by a computer.
In defense computers are used in electronic news gathering, efficient communications, detection and tracking of terrorism, radar systems in Airports.
Computers are also used in warning and guiding missile systems.
THE COMPUTER SYSTEM
Refers to a system of interconnected computers device that share a central storage system and other peripheral devices such as printers, scanners or routers in order to communicate.
COMPONENTS OF A COMPUTER SYSTEM.
The basic components of the computer are:
HARDWARES
SOFTWARES
HUMANWARE/ORGWARE
FIRMWARE
1.HARDWARES
These are all the physical and tangible parts of the computer system.
They include the following categories of hardware.
Input devices.
These are devices that allows the user to enter data into the computer system.
They include-keyboard, mouse, keyboard, mouse, Digital cameras,
Joysticks-used in playing games
Scanners-Captures graphical texts and drawings into the computer system.
Other examples of manual input devices are:
Remote control, Touch screen, Calculator (numeric keypad), Microphone,
Graphics Tablet, Webcams (used in computers)
Output Devices
These are the devices used to provide the user with the results after data has been processed.
Output devices they include:
Monitor/screen/VDU (Visual Display Unit). Information displayed on the screen prior printing is called softcopy
Printers. These are the output devices used to output data in hardcopy (touchable data on paper) or print out.
Plotters. A plotter is a graphic printer that draw images with ink pens.
They are also used in printing graphics on large paper sizes and full-sizes engineering and architectural drawings, produce Maps, Charts etc.
Speakers-produce information in form of sounds.
c)Input/Output devices
These are devices that work both as input/output devices e.g. You can have a printer that can also be used as a scanner.
Touch screen
Smart phones
Tablet computers.
d)Central Processing Unit (CPU)
It’s the heart and brain of a computer
The CPU consists of 1 or more Integrated Circuits
The CPU has 3 Main parts
Control Unit (C.U)
Arithmetic logic Unit (A.L.U)
Main Memory Unit (MMU)
i) Arithmetic Logic Unit (ALU)
Performs arithmetic calculations such as (*, +, /&-)
ii)Control Unit (CU)
It controls, supervises and oversees all the activities taking place in the computer system.
It also interprets the instructions and issues signals so that the hardware excites them as requested.
iii)Main Memory
There are Two main type of Memory in a microcomputer i.e.
i)RAM (Random Access Memory)
The name Random Access means that the information in any area of the RAM can be read or accessed in the same amount of time randomly using a technique called algorithm generated address/mathematical procedure.
Characteristics of RAM
Its volatile-when power goes off without saving your work you lose all the data.
Data stored in RAM are Temporarily
You can read and write on the RAM
ii)ROM (Read Only Memory)
The contents of ROM cannot be altered
The contents of this memory can be retrieved/read and cannot be written on it thus you use the contents the way they are because it’s designed by the manufacturers of that product.
Characteristics of ROM
Its non-volatile: its contents remain intact even when the power goes off.
Stores data permanent.ie.its contents can be read but cannot be written during normal computer operations. The same contents are used when computer is booting.
E) OTHER STORAGE DEVICES INCLUDE:
NB/Primary storage device/internal storage is the HARDDISK-inside the system unit.
Secondary storage/Auxiliary storage are: Auxiliary CARD, Google drive, sky drives etc.
F) Communication Devices e.g., MODEM
Modulator Demodulator-changes analogue signal to Digital signals and vice versa.
2. SOFTWARES
These are programs that makes the computer hardware’s to function.
A program is a set of instructions in a language known to a computer telling it what to do.
We’ve two types of Software i.e.
System software
Application software
SYSTEM SOFTWARE
These are programs that deal with solving the problems of computer Hardware’s.
These are Hardware oriented programs.
They are farther divided into:
Operating System
Language Translators
Programing languages
Utility Programs
Operating System
It’s a program that helps to control and manage the operations of the computer system.
Operating system acts as an interface between the user and the computer hardware and other software.
It’s the most important program in the machine.
Without the operating system the computer cannot function.
FUNCTIONS OF OPERATING SYSTEM (O.S)
Process management-The oz.’s keeps track of all activities taking place in the machine.
Resource Management-The oz.’s allocates system activities to the CPU, Main memory, input/output devices etc.
Data management –The oz.’s handles the movement of data between the components of the system.
Error detection and correction-The oz.’s detects errors caused by other programs, hardware and issues a suggestion on how to rectify them.
TYPES OF OPERATING SYSTEM
Single user single program operating system e.g., MS DOS
Multi-program multi-tasking oz.’s e.g., Windows
Examples of operating system in the market are:
Microsoft windows (its Versions are, windows Pindos 7, windows 8 etc.)
Ubuntu (open source)
MS Dos etc.
ii) Language Translators
It’s a program that translates human understandable language to machine code language and vice versa so that communication can take place.
There are three types of language translators i.e.
Assemblers
Compilers
Interpreters
iii)Programing languages
These are programs that are used to develop other useful programs.
For example, C++, JAVA, VISUAL BASIC etc.
iv)Utility Programs
It’s a program that provides a certain unique services to the computer. For example: scan discant-virus
Application software
These are programs that are used to solve user problems
They are farther divided into
User Defined Program
Application packages
User Defined Program
These are programs that are used to solve specific user problems.
They can also be referred to as Tailor made programs Geoff-shelf programs
Application packages
They are classified into:
Word processors
Spreadsheet
Database programs
Accounting packages
Communication programs
Presentation programs
Engineering and Architectural programs.
3.HUMANWARE/ORGWARE/LIVEWARE
These are the people who work with computers.
They are farther divided into 5 Categories:
Users
Designers
Developers
Technician
IT security personnel.
MODULE TWO: KEYBOARD AND KEYBOARDING PROFILE
Objectives:
KEYBOARD-
It is an input device used to feed data into the computer.
The keyboard has several keys. These keys differ from each other.
TYPES OF KEYBOARD
Mechanical key switch keyboard
They are mostly used with desktop computers and they can also be used with laptops
These keyboard works by use of individual switch for each keyboard.
Capacitive keyboard
These keyboards are used in laptop computers, they take up less space.
NB/keyboard are divided into several parts i.e.
FUNCTION KEY.
These keys range from F1-F12.These are multi-purpose keys.
This means the function of each key change from one program to another.
e.g., f1-help, f4-refresh, f7-spelling and grammar check.etc.
ALPHANUMERIC KEYS.
These are keys containing e.g., as well as spacebar.
Standard keyboard uses QWERTY layout.
MODIFIER KEYS/SPECIAL KEYS
They include ALT, CTRL&SHIFT.
These are special keys on a computer keyboard that modifies the normal action of another key when pressed in combination.for example.
ALT+F4-exit/close active window running.
CTRL+S-Saving changes to a document.
Ctrl+p- print
Ctrl+v-paste
Ctrl+x-cut
Ctrl+c-copy
Ctrl+esc-open start menu
CTRL+Z-undo last action
Ctrl+y-redo last action.
Ctrl+d-display fonts
Ctrl+n-new document
Ctrl+o-open a document
Ctrrl+e-align center
Ctrl+r-align right
Ctrrl+l-align left
Ctrl+j-justify text.
Ctrl+a-select all
Ctrl+u-underline.
Ctrl+i-italics
Ctrl+b-bold
EDITING KEYS
They include-Backspace,Insert&Delete keys.They enable additional control over a document.
SYSTEM KEYS
Print screen,esc.
Print screen is used to capture the screen.
Esc key is used to initiate escape signals.
6.LOCK KEYS
They include-Num lock, Cap’s lock and scroll locks.
These keys lock part of the keyboard depending on the selected settings.
7.TABS KEY
It’s used to create an indent.
8.WINDOWS KEY
They are used to display a start menu and a shortcut menu for windows program.
9.NAVIGATION KEYS/CURSOR MOVEMENT KEYS/ARROW KEYS.
They are marked with arrows and control the cursor movement.
The cursor is the blinking line on the screen, which helps in typing text.
The Home screen, which up, page down is part of navigation keys.
10.NUMERIC KEYPAD
These are keypad on the right hand side of the keyboard.
They range from 0-9.
We use these keys to enter data in form of numbers, perform calculations and controlling the movement of cursor especially if the num lock is activated.
MICROSOFT WINDOWS BASICS
WINDOWS DESKTOP
The desktop is your work area on which program and files icons are located. It is basically a workspace where you can access everything you need to operate your computer, such as system components, applications, the Internet, etc
Parts of the Desktop
1. Start button: The start button allows you to open menus and start applications.
2. Taskbar: It is primarily used to switch between open windows and applications.
3. Icons: These are pictorial representations of applications, files, folders and other parts of the operating system.
4. My Computer: The “My Computer” icon provides access to the resources on your computer e.g. Disk drives such as Drive C
5. Internet Explorer: The internet explorer icon launches the Internet Explorer browser.
6. My Network Places: If you are working on a network, this displays all of the computers on the network.
7. System Tray: The part of the taskbar that holds the clock, volume control, and icons for other utilities that runs in the background of your system.
8. Recycle Bin: This is a temporary storage location for deleted files and folders.
PARTS OF AN APPLICATION WINDOW
Title Bar: This is a bar across the top of the window that displays the name of the current application program or task.
Menu Bar: Menu bar provides a list of commands that can be used to manipulate a task. E.g. Insert, Page Layout, View, etc.
Toolbars: These are buttons arranged in a row that are shortcuts to menu commands.
Work Area: This is where you organize your work within a program.
Status Bar: Displays information about the program e.g. page number, number of words, etc.
Scroll Buttons: They are used to move the window up/down or left/right in order to view the hidden parts of the window.
Minimize button: It reduces a window to appear as a button on the taskbar.
The restore/maximize button: It stretches the window to cover the entire desktop or restores it to its original size.
Close button: It is used to exit an application
CHANGING THE DESKTOP BACKGROUND
1. Click Start button.
2. Click Control Panel.
3. Click Appearance & Personalization.
4. Click Change desktop background.
5. Choose the background you want to set.
6. Click Save Changes.
SCREENSAVER
A screensaver is a computer program that blanks the screen or fills it with moving images or patterns when the computer is not in use.
Importance of a Screensaver
1. Screensavers increase your privacy, as well as security. If you are working with confidential data you wouldn’t want others to see, the screensaver will eventually cover this data on your screen up after a certain amount of time.
2. A screensaver is used for entertainment purposes.
CREATING A SCREENSAVER
A. SETTING THE IMAGE
1. Click Start button
2. Click Control Panel.
3. Click Appearance and Personalization.
4. Under Personalization, click Change screen saver.
5. Under screensaver area, select the screensaver required e.g. Bubbles, Mystify, Photos, Ribbons, etc.
6. Click OK.
B. SETTING A 3-D TEXT SCREENSAVER
1. Click Start button
2. Click Control Panel.
3. Click Appearance and Personalization.
4. Under Personalization, click Change screen saver.
5. Under screensaver area, select 3-D Text.
6. Click Settings.
7. In the Custom Text area, type your name/ text.
8. Set the Rotation Type, Colour, Rotation Speed and Size.
9. Click OK.
MODULE THREE:MS DOS(Microsoft Disk Operating system)
Objctives:
Ms Dos –It’s a program that:
Controls the computer system
Links the user with the computer
Controls the computer resources and the pheripheral devices.
Rules governing naming of files.
Filenames are not case sensitive.
Maximum length allowed for a filename is 8 characters.
Maximum length allowed for the extension to a file name is 3 characters.
The filename and extension are separated by a period(.)
Punctuation marks(‘,?>”!{}[] and spaces are not allowed because they’ve special meaning in Ms Dos.
How does Ms Dos works?
Ms Dos works by use of commands
It’s a single- user ,single-tasking operating system(ie. It can run only a single application at a time)
It does not support multi-media ie.it does not support graphics and sounds.
It uses keyboard to type commands.
Ms Dos works in two type of commands:
Internal commands
External commands
These commands are entered on the Ms Dos prompt eg.C:\>or A:\>
Internal commands
These commands are loaded automatically when the computer starts.
Examples of internal commands are:
Time
Date
Ver
Vol
Dir
Cls (clear screen) to create space to type new content.
Copy con
Type
Copy
MD (make Directory)
CD (change Directory)
CD\ (used to change to the root Directory)
CD.. (used to move back one level above the current Directory)
External commands
These commands require special type of files to be executed.
They are loaded into the memory only when called, they are then found in separate files on Hard Disk or Floppy Disk,so that they don’t typically consume valuable memory space.
Examples of External commands:
Tree
Edit
Label
Working with files and Directories:
What is a file?
A file is the smallest unit of storage.The name given to a file should be related to the content it contains.
Elements of a file: A file consists of:
File name
Period
Extension
Date
Time
Bytes
A file name is that name given to the file.A file name should not exceed 8 characters.ie.
Command.com
File name Extension.
A period separates the file name and extension(.)
An extension identifies the type of files and should not exceed 3 characters.
NB:Extension is not a must.(some files do not have extension).
EXAMPLE OF EXTENSIONS
Com-These are command files that control the programs
Sys –system files
TXT-text files
DOC-Document files
Exe-These are excutable files that make program run.
The date indicate when the file was created (current date of the computer).
The time indicate the time when the file was created.
The bytes indicate the number of characters in a file. A byte is a character.
Ms Dos prompt
Ms Dos prompt indicates that Ms Dos are ready to accept commands.
C:\>
A:\>
WORKING WITH COMMANDS
1.DIR
Dir command displays/list all files in a directory or drive.shows
Filename -Date
Extension -Time
Bytes
Syntax: C:\>DIR [ENTER]
2.TIME
Time command displays the current time and enables you to enter new time.
Syntax: C:\>TIME [ENTER]
3.DATE
The date command shows the date when the file was created or modified and enables you to enter new date.
Syntax:C:\>DATE [ENTER]
4.VER
Shows the Ms Dos Version
Syntax:C:\>VER [ENTER]
5.VOL
Vol command displays the volume label of a disk.
Syntax:C:\>VOL [ENTER]
6.COPY CON
This creates a file in Ms Dos.
Syntax:C:\>COPY CON
This creates a file in Ms Dos.
Syntax:C:\>COPY CON {FILENAME} [ENTER]
“Type the text you want” then to save your text file hold down the CTRL+Z OR press F6 (function key)
Then you will see 1file copied.
7.TYPE
The type command is used to see the content of a file.
Syntax:C:\>TYPE {FILENAME} [NTER]
CREATING FILES
Files can be created in word processors,Database and other packages,also they can be created directly from Ms Dos commands. We have two ways of creating files:
Copy con
Edit
Copy con
Type the command copy con followed by filename period extension then press enter.
Type the content of the file
Save or close by pressing F6 or CTRL+Z
Press enter key. You will see 1file copied.
Syntax:copy con {filename}<enter>
Type the content……………………………………………………………………….
…………………………………………………………………………………………………………
………………………………………………….F6 or Ctrl+z<enter>
Edit
This is an advanced way of creating files in Ms Dos using the full screen editor window known as Ms Dos editor,which allows you to edit,save and print.
Syntax:c:\>edit {filename}<enter>
NB: To save your work in Ms Dos editor press ALT key on the keyboard,then press F,then S.
To exit the ms dos editor window press ALT,then F, and then X.
8.COPY.
This command helps to ake a duplicate of a file.It copies file contents from a source file to a destination file.
To copy the contents of a file to a new file.
Syntax:C:\>COPY (source filename) (destination filename)<enter>
MODULE FOUR:MS WINDOWS
Objctives:
Microsoft Windows is an operating system developed by Microsoft corporation.
Windows like any other operating system it links the user with the system,manages computer resources and controls how computer works.
Windows is a Graphical User Interface(GUI) operating system.
Graphical User Interface,is a type of interface that allows the user and the computer to communicate by use of Icons(pictures).
Windows has an outstanding features known as WIMP(windows,Icons,Menus &Pull down tabs)
Desktop properties:These are features found on the desktop when you open a computer.
Example of Desktop properties:
Icons
Taskbar
Icon-is a small pictogram used as a graphical user interface.
Taskbar-It’s found at the bottom of a screen and it is divided into 3 parts.
Start button-It contains start menu commands.
Task plain-It displays the name of the running program.
System tray/Notification area-It displays time,date and protection status of a computer.
Main computer Icons are:
My document-This is used to store documents and files within a computer.
My computer-it displays features of a computer e.g.Size of the memory,drives installed etc.
My network places-It shows shortcuts to websites and network computers.
Recycle bin-It contains deleted files and folders(documents)which can be restored.
Changing the Background of a computer.
Right click on the blank space on the desktop
Select properties
Click desktop
Choose background of your own choice.
Click apply then ok.
Applying the screensaver
Right click on the blank space on the desktop
Select properties
Click screensaver
Choose screensaver of your choice
Click apply then ok.
Resetting date and time.
Double click at the system tray where the time is being displayed.
In the part of month choose the correct months.
In the part of date choose the correct date.
In time set the correct time and click apply then ok.
Creating Folders
A folder is a logical container that we can use to organize files.
You can create sub-folders under the main folder.
A default folder in a harddisk is my documents.
How to create a folder.
Right click on the blank surface on the desktop
Select new
Click on it type name of your choice then press Enter.
How to Rename a folder.
Right click on the folder which you want to rename.
Type your desired name and press Enter.
How to Delete a folder.
Right click the folder you want to delete
Then select delete.
Creating Files
A file is an electronic document created in any given application.
It’s used to store related documents.
How to create a file.
Right click on the blank part of the screen.
Select new then point at text document and click
Type the file name then press Enter.
ACCESSORIES.
These are the programmes that come together with the operating system.
They include:
Calculator
Notepad
Wordpad
Ms paint
System tools etc.
Calculator
Calculator are programmes that are used to perform simple and complex calculations.
How to Start a Calculator.
Click the Start button
Point on Run and type “Calc”
Click ok.
Notepad/wordpad
This is a word processor program that we use to type,edit,format,spelling check and printing of professional documents like:
Letters
Reports
Minutes etc.
Procedure of starting wordpad.
Click the start button
Point to all programs
Select accessories
Then point at wordpad.
Ms paint
Click on start button
Click programmes
Click accessories
Select Ms paint
Using the tools make a drawings of your own choice.
After drawing save your work in an appropriate location eg.
Desktop, my documents, my computer.
SAVING A DOCUMENT
Click on file menu
Then select “save as”
From the resulting box select the location of the file i.e. either
My documents
Folder or Removable media.
Type the file name then click save.
MODULE FIVE:MS WORD (Microsoft word processor).
Objectives:
1. Define word processor.
2. Give examples of word processor.
3. Discuss uses of word processor.
4. Starting Ms word and Discuss parts of word window.
5. Typing a document
6. Save a document in a folder, Flash disk, or on the Desktop.
7. Saving a document with a password.
8. Editing texts: a)Copy and paste
b)cut and paste
c)Find and Replace
d)spelling and grammar check
e)Thesaurus.
9. Formatting text.
10. Inserting Options
11. Tables
12. Mail Merge.
1.Define word processor.
It is a program that we use to type,edit,format,spelling check and printing of professional documents like: Letters, Repports,Minutes etc.
2.Examples of word processor.
Ms word
Notepad
Wordpad
Word perfect
Word star etc.
3.Uses of Ms word
Used for preparing documents like: Books, letters, Minutes, Newsletters, Magazines, Preparing charts, tables, Mail Merging Letters etc.
4.Starting Ms word
Click on the start button
Click on programmes
Select Microsoft Office
Then select Ms word 2007.
Or
Press and hold down Windows key on the keyboard
On the Run box displayed type “winword”
Then press enter or click ok.
5.Parts of word window.
Title bar
Control button
Typing area(working area)
Office button
Rullers
Scroll bar and scroll buttons.
Dialogue box Launcher.
Ribbon/groups tab.
Windows border
Zoom level area.
Quick access tool bar.
6.Saving a document
We use “save as” command to save a document for the first time or give file a new name.
“Save” command is used to save changes made on an existing document.
7.Saving a document with a password
To protect a document against an authorized access save a document with a password.i.e
Click on File menu/Office button and select save as, then select general Options then input your password and click save.
8.Editing texts
a) Copy and paste-Enables you to make a duplicate/copy of information/text document
b) Cut and Paste-Enables you to delete the highlighted texts or original information and then retain new information.
c) Find and Replace-Enables you to replace a certain word with another.
d) Thesaurus-This is a tool that provides a synonyms.
e) Spelling and grammar check-Enables you to recognize any spelling error or grammatical errors.
9.FORMATTING TEXT.
This is a method used to enhance the appearance of a document.This can be done through:
a).Font type, Size, colour, underline, Italics, Bold etc
b).Change Case
c).Tabs (you tab before you type a text at the beginning of a sentence.
d).Columns
e).Bullets and Numbering.
f).Indenting, line spacing.
g). Alignment ie.Right,Left,Centre,Justify.
h). Borders and shading, Superscript & subscript.
NB:For you to apply any of these formatting components you have to highlight your document/ word first.
10.INSERTING OPTIONS.
Word Art
Clip Art
Smart Art
Shapes
Charts
Headers and footers
Symbols
Cover page
Page numbers
Drop Cap
Date and Time
11.TABLES
Insert tables
Enter text in a table
Add and Remove rows and columns
Performing Calculations in a table.
Merging cells
12.Mail merge a letter.
INTERNET
It is a large network of networks that covers the whole world and enables millions of computers from different organizations and people to communicate globally.
Importance of Internet
The importance of internet can be seen through its contribution to:-
a) Research activities
b) News and information dissemination.
c) Leisure
d) Communication.
e) Business Transactions, etc.
Requirements for Internet Connectivity
(a) Telecommunication facilities
Internet relies on telecommunication facilities like telephone lines, telephone exchange station and satellite transmission in order to cover the whole world.
(b) Modem (Modulator-Demodulator)
It is a special digital to analog interface card that changes data from digital to analog so as to be transmitted on telephone lines and on receiving end the data is changed from analog to digital for the computer to understand.
(c) Internet Service Providers (ISP’s)
These are companies that offer internet services to end users. They provide the Internet services to end users at a fee.
Examples of ISP in Kenya include:
1. Liquid Telecom
2. Access Kenya
3. Zuku
4. Faiba
5. Telkom Kenya
6. Safaricom
(d) Internet Software
Internet software help facilitate your access to the Internet. To achieve communication between computers special software called Protocol is needed.
INTERNET SERVICES
1. E-mail
This is the exchange of electronic letters, data and graphics on the internet.
2. Electronic Learning (E-learning)
This is learning through interaction with special programs on the computer.
3. Electronic Commerce (e-commerce)
It refers to buying and selling of goods and services over the internet.
4. World Wide Web (WWW)
In order to connect a network to the internet, the local area network needs an internet server. This server is given the name world wide web (www) and has all the information which others on the internet access.
ACCESSING THE INTERNET
Software applications that enable the user to access information on the internet are called Web Browsers. Examples of web browsers include:
· Mozilla Firefox
· Netscape Navigator
· Google Chrome
· Opera
· Internet Explorer
· Safari
I Login/ Sign In
To access a website, type the full address of the website on the address bar, then press the enter key.
Surf/ Browse
Surfing/ Browsing is the process of accessing Internet resources like web pages and websites.
Hyperlinks
A hyperlink is a text or picture on an electronic document that causes other web pages to open when the link is clicked.
Search Engine
This is a program that searches documents for specified keywords and returns a list of the documents where the keywords were found. Examples of search engines include: Google, Yahoo, Bing, Ask, WebCrawler, etc.
Downloading
This refers to the process of transferring information from the internet to a local storage e.g. a computer, flash disk, etc.
Uploading
Refers to the process of transferring a file /files from your computer to the Internet.
ELECTRONIC MAIL (E-MAIL)
Electronic mail refers to the sending and receiving of electronic letters and documents on the internet.
E-MAIL SOFTWARE
E-mail software falls under communication software that are designed to help the user to read and send individual text documents on the internet so long as the sender and receiver have an e-mail address. Examples of e-mail software include: Gmail, yahoo, hotmail, outlook express, thunderbird, etc.
E-MAIL FACILITIES
1. MAILS
a) Checking Mail
In order to check mail the user has to open the e-mail account by providing the correct username andpassword. In e-mail account, click the Inbox command to view a link list of all received mails.
b) Compose a Mail
Composing implies writing. To compose a message, click the Compose command.
c) Send Mail
To send mail, type the correct e-mail address of the recipient, and then click Send command.
d) Forward Mail
A received mail can be forwarded to another recipient. After reading, click the Forward command and then provide the address of the recipient.
2. FILE ATTACHMENT
E-mail software enables a person to attach other files like pictures, music, movie clips, etc to an e-mail for sharing with others before sending. The source of attached files can be from the hard disk or other storage devices.
3. ON- LINE MEETING
It is possible to hold an on-line meeting with people by sending mails to them e.g. on-line interviews may involve a person sending electronic mail composed of interview questions to a recipient who can read and answer back.
4. TELEPHONE MESSAGES
Wireless Access Protocol (WAP) makes it possible to send e-mail to a mobile handset and a mobile message to e-mail account.
5. CONTACT MANAGEMENT
Most mail programs allow the user to develop an address book which holds contact information like e-mail address of different people.
E-MAIL ADDRESS FORMAT
A typical e-mail address would look like this:murimi@pctechkenya.com
murimi is the username and is usually created by the user during e-mail account registration.
@ is the symbol for “at” which separates the user name from the rest of the address.
Pctechkenya.com is the name of the host computer in the network i.e. the computer on which the e-mail account is hosted.
Com identifies the type of organization offering a particular service(s) and is called the domain, meaning it is a commercial institution.
OTHER COMMONLY USED DOMAINS INCLUDE:
|
DOMAIN |
TYPE |
|
.edu |
Educational Institution |
|
.gov |
Government Institution |
|
.org |
Non- profit making organization |
|
.mil |
Military organization |
|
.co |
Commercial Institution |
|
.net |
An institution or organization providing networking services |
|
.ac |
An academic institution |
E-MAIL COMPOSE WINDOW
A typical e-mail compose window has three basic elements:
1. HEADER: The e-mail header is made up of the following parts:
(a) Addresses of the Recipients: The e-mail recipients can be more than one.
(b) Subject: Presents the topic of the message.
(c) Attachment: Files attached from other programs such as word processors and spreadsheets.
2. MESSAGE: This is the content of the email. It is typically short and to the point. It may include text and graphics.
3. SIGNATURE: The signature provides additional information about the sender such as full name, address and telephone number.
ATTACHING FILES INTO AN E-MAIL
1. Click the Attachment button on the toolbar.
2. In the Dialog box that appears, select the file/ files to attach.
3. Click Attach button to attach the files.
COMPUTER VIRUS
“A computer virus is a program that may disturb the normal working of a computer system”. Virus attaches itself to files stored on floppy disks, USBs, email attachments and hard disks. A file containing a virus is called infected file. If this file is copied to a computer, virus is also copied to the computer.
Activation of Virus
When the computer virus starts working, it is called the activation of virus. A virus normally runs all the time in the computer. Different viruses are activated in different ways. Computer viruses cause billions of dollars’ worth of economic damage each year, due to causing systems failure, wasting computer resources, corrupting data, increasing maintenance costs, etc”.
Damages caused by virus
Computer virus cannot damage computer hardware. IT may cause many damages to a computer system. A virus can:
A computer virus can damage data or software on the computer.
It can delete some or all files on the computer system.
It can destroy all the data by formatting hard drive.
It may display a political or false message very few times.
Causes of Computer Virus
The following are the main causes of a Computer Virus.
1. Infected Flash Drives or Disks
Flash drives and disks are the main cause of spreading viruses. Flash drives and disks are used to transfer data from one computer to other. A virus can also be copied from one computer to other when the user copies infected files using flash drives and disks.
2. Email Attachments
Most of the viruses spread through emails. Email attachment is a file that is sent along with an email. An email may contain an infected file attachment. Virus can spread if the users opens and downloads an email attachment. It may harm the computer when it is activated. It may destroy files on the hard disk or may send the virus automatically to all email addresses saved in the address book.
3. Infected / Pornography websites
Thousands of insecure websites can infect computer with viruses. Most of the websites with pornographic materials are infected, so by visiting these websites the user’s computer also gets infected by virus. These websites are developed to spread viruses or other unethical material. The virus is transferred to the user’s computer when this material is downloaded. These websites may access the computer automatically when the users visit them.
4. Networks
Virus can spread if an infected computer is connected to a network. The internet is an example of such network. When a user downloads a file infected with virus from the internet, the virus is copied to the computer. It may infect the files stored on the computer.
5. Pirated Software
An illegal copy of software is called pirated software. Virus can spread if user installs pirated software that contains a virus.
How to protect your computer
A computer system can be protected from virus by following these precautions.
1. The latest and updated version of Anti-Virus and firewall should be installed on the computer.
2. The Anti-Virus software must be upgraded regularly.
3. USB drives should be scanned for viruses, and should not be used on infected computers.
4. Junk or unknown emails should not be opened and must be deleted straightaway.
5. Unauthorized or pirated software should not be installed on the computer.
6. An important way of protection against virus is the use of back up of data. The backup is used if the virus deletes data or modifies it. So, back-up your data on regular basis. There is some great software that can back up your data automatically.
7. Freeware and shareware software from the internet normally contain viruses. It is important to check the software before using them.
8. Your best protection is your common sense. Never click on suspicious links, never download songs, videos or files from suspicious websites. Never share your personal data with people you don’t know over the internet.
Cyber crime or internet crime
Cybercrime, or computer-oriented crime, is crime that involves a computer and a network. The computer may have been used in the commission of a crime, or it may be the target. Crimes that use computer networks or devices to advance other ends include: Fraud and identity theft (although this increasingly uses malware, hacking or phishing, making it an example of both "computer as target" and "computer as tool” crime) Information warfare.
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