IGCSE ICT

tablet and Desktop

A tablet has a much smaller screen and has fewer components than a laptop computer, which makes for a longer battery life. Desktop and laptop computers come with more fully featured operating system due to having the computing power and memory requirements.

types of software

1. System Software
System software is a collection of one or more programs used to control and coordinate the hardware and other application software.
Generally the system software may perform the following functions:
• Communicates with hardware devices. Controls and monitors the proper use of various hardware resources like CPU, memory, peripheral devices like monitor, printer etc.
• Supports the execution and development of other application software.
Few examples of system software are:
• Operating system
• Programming language translators
• Communication software
• Compiler and Interpreters
• Command line shell
2. Application Software
Application software is a collection of one or more programs used to solve a specific task.
Generally software used in banking industry, airline/railway reservation, generation of telephone or electricity bills etc. all fall under application software.
Few examples of application software are:
• Word processing software
• Spreadsheet software
• Database software
• Education software
• Entertainment software
3. Utility Software
Utility software is a collection of one or more programs that helps the user in system maintenance tasks and in performing tasks of routine nature. Utility programs help the users in disk formatting, data compression, data backup, scanning for viruses etc.
Few examples of utility software are:
• Anti-virus
• Registry cleaners
• Disk defragmenters
• Data backup utility
• Disk cleaners

normal, abnormal and extreme test data
Normal Data – Data that should be accepted
Abnormal Data – Data that should be rejected (not expected data)
Extreme Data – Data that pushes the boundaries (data outside normal limits)

Example – Month number (1-12):
Normal Data – 5
Abnormal Data – August
Extreme Data – 17
Router and Modem
A router is a small box that allows multiple computers to join the same network
In order for devices on the network to connect to the Internet, the router must be connected to a modem.
The word modem is actually short for Modulator/Demodulator. A modem is a communications device that can be either internal or external to your computer. It allows one computer to connect another computer and transfer data over telephone lines. The original dial-up modems are becoming obsolete because of their slow speeds and are being replaced by the much faster cable and DSL modems.
A digital subscriber line (DSL) modem is a device used to connect a computer or router to a telephone line which provides the digital subscriber line service
the device connection order is outlined below:
1. PC or wireless device
2. Router
3. Modem
4. ISP (Internet Service Provider) AT&T, Verizon, Comcast, or BrightHouse
5. Internet

Types of Processing
There are three different ways computer process the data.
They are:
1. Batch processing
Batch processing is done when there is large volume of data to be processed like preparing electricity bills for 50,000 customers.
Batch processing is collecting all relevant data together, input them to computer and process them in one batch.
Examples for batch processing:
• Electricity bill preparation
• Water bill preparation
• Preparing salary slip for all the employees in a company
• Bank prepare credit card bills for its customers
• Processing cheques, etc
• Updating a stock database
Advantages of Batch processing
Processing can be done when computer is not used for anything else.
Once started, processing will continue automatically without any human intervention.

2. Real time Processing
Sometimes the data need to be processed immediately and there should not be any delay in getting the output.
Real time systems process data immediately and produce the output before the next input.
Real time systems respond very quickly when there is any input.
Examples for real time processing
• Booking of flight ticket
• Patient monitoring in the ICU – Computer alerts the nurse immediately if any of the patient condition goes abnormal.
• Real time processing example – Flight booking
Input – Please reserve seat 12C
Process – Has seat 12C already been booked? No… so book it.
Output – Booking confirmed for 12

3. Online processing
An online processing is where the user is directly interacting with a remote computer. User input data directly into the system and then it is processed.
Example for online processing:
• Booking a train ticket using internet.
• Booking a cinema ticket.
• Ordering for a book online.
• Managing a bank account online

Browser and Search engine
browser is used to access various websites and web pages. A search engine is also a software program that searches for some particular document when specific keywords are entered. Internet Explorer, Firefox, Safari, and Opera, are examples of browsers. Google and Yahoo are the most popular search engines