• Radiowaves are omnidirectional while microwaves propagate in one direction at a time(unidirectional)
• Radiowaves can be propagated over long distances through sky mode while microwaves require a relay satellite to amplify and retransmit the microwaves signals to the receiver earth station

• an attribute/combination of attributes chosen to ensure that the records in a table are unique

1. Speeds up coding since converting a pseudocode into a programming language is usually faster and easier
2. Acts as documentation
3. Simplifies debugging since logical errors can be identified and corrected early in design stage
4. Language independent since it is not tied to any specific language so can be translated into different languages
5. It uses simple english-like statements

• Object code refers to a program in machine language while source code to a program in a high level language that must be translated to object code for it to be machine readable

• It is a utility software that places file data in adjacent sectors to free up space for more data and reduce access time for files stored

• confidentiality - The principle of protection from unauthorized access or disclosure
• Integrity - the principle of ensuring that unauthorized or undetected changes to data or system configurations do not occur.
• Availability - the principle of ensuring that data and services remain accessible to authorized users at all times

• System software that analyses, configures, optimises and maintains a computer system

• Outsourcing is the practice of using third-party providers to perform services and/or create goods that would traditionally be done within the business.

• To provide legal backing so that it is possible to seek redress if the rights are violated
• To observe copyright for those who create original works
• To protect the confidentiality of information kept  about an individual

• A laser printer makes use of powdered ink and static electricity to print
• Unlike inkjet printers which print line-by-line, laser printers print the whole page in one go

Steps

• The data from the  file to be printed is sent to a printer driver
• The printer driver checks that the data is in an understandable format
• The printer driver checks if the printer is able to carry out the print job
• The data is sent to the printer and is stored in a printer buffer
• A printing drum in the printer is given a positve charge. A laser beam removes the positive charge in some areas. This leaves negatively charged areas which matches the characters/images to be printed
•  

• novice can use the system right away
• user-friendly/easy to select
• click on icons/picture to select
• easier to input/words are replaced with icons
• no need to know command language to use the system/remember
• command language
• selecting item using mouse is faster than entering commands
• avoids typing errors
• no need to type
• no need to remember commands
• no need know the different commands for the different software
• multitasking (several programs open at the same time therefore easier
• /faster to switch
• easier/faster switching between files, folders etc.

Word wrap - Is a word processing feature in which a word that does not fit in the current line is automatically moved at the start of the next line

Justification - refers to aligning text on both left and right margins

Drop cap - Make the first character of a paragraph occupy more than one line below it

Define the term internet      1mk

• The global interconnection of computer networks for purpose of communication and resource sharing

Explain the term web page    1mk

• A hypertext  page prepared to display the content on the web

Explain the following internet address http://www.google.co.us in reference to the structure of a URL    3mks

• HTTP- hypertext transfer protocol or simply protocol
• WWW – subdomain
• google – the name of the computer with the web content/domain name
• .co – top level domain for commercial organization
• .us- a TLD extension for the country US

What is the world wide web                                       1mk

•  A virtual space on the internet that allows web pages and sites to be accessed

Define the term browser                                    1mk

•  A software that used viewing of web content

Explain the meaning of the word hyperlink     1mk

• A text or picture that is a link to another webpage on the internet

What is a search engine?     1mk

• Is a special program that collects and stores links to information websites allowing users to search its database for them
• A specialized web-based application that help the user to search for specific information on the internet.

Explain the meaning of the term internet service provider            1mk

• A company that offers internet services to end-users

Identify three elements apart from a computer that is required for one to be connected to the internet    3mk

• Modem
• Internet software
• Internet service provider
• Telecommunication lines
• TCP/IP protocols

Define the term modem 1mk

• Stands for modulator-demodulator
• A device that enables telecommunication to use telephone lines

What is a protocol? Write the following in full: TCP/IP, HTML, HTTP and FTP           5mks

• Protocols – are special communication rules that govern sending and receiving of messages by computers on a network
• Html – hypertext markup language
• Hypertext transfer protocol
• Transmission Control Protocol
• Internet Protocol
• File Transfer Protocol

What would you do if a website refused to load on the browser within the first attempt?   1mk

• Click the refresh button on the toolbar

 State three internet services                         3mks

• Instant messaging
• E-mails
• E-commerce
• Social media and networks
• E-learning

Define the term internet telephony      1mk

• Transmission of voice data over the internet

State three benefits of the internet in our society

• Provides a platform for conducting business and marketing
• Provides many platforms such as social media through which people can contact each other
• Cost saving
• Efficient communication

(a) Buffer

• temporary storage or memory which compensates for the difference speed of peripherals and the CPU

(b)batch processing

• processing doesn’t start until all data is collected
• JCL (any reference to Job Control Language)
• no need for user interaction
• processed all in one go
• done at “quiet” times
• e.g. billing, payroll, cheque processing

(c) e-commerce

• electronic commerce
• buying and selling products/services using the internet/computer networks

(d) simulation

• studying the behaviour of a system by using a model/mathematical representation
• results can be predicted
• e.g. flight (or other) simulator, modelling hazardous chemical process

(e) Email

• sending messages from one device to another using computer networks/Internet

• Real-time OS reads information from input devices and must respond within a short duration of time to ensure correct performance
• Distributed OS distributes computation among several physical processors which do not share memory or clock

• It requires that a foreign key must have a matching primary key or it must be null

• Application software refers to software that is designed to help the computer user to accomplish specific tasks
• Examples of application software include; Internet browsers, word processors, spreadsheets, databases etc
• System software is software that performs tasks needed to operate the hardware and provide services to other software
• Examples Operating Systems, Networking software, utility programs(encryption, backup, disk defragmentation software, ...)

• Data enters at one end (of a stack)
• Leaves at the same end
• Hence 'last in, first out'

The user is not allowed to access the source code so, they cannot tailor the software to their needs and  they cannot fix any bugs in it

The software is still covered by copyright

The user must get the owner’s permission to do anything beyond using it

Many components that go into computer systems are toxic and dangerous to the environment if released or disposed of inappropriately.
Heavy metals are used in batteries and circuits and these can pollute groundwater or kill animals if left exposed on landfill. Large quantities of plastics are used in systems, which take a long time to break down, some of the plastic will eventually break down into toxins as it degrades.