Chapter 1: Types and components of a computer system IGCSE

hardware

the physical components that make up a computer system, e.g: keyboard, mouse and monitor. Hardware can be external or internal.

Software

Programs that control the computer system. There are 2 types of software: application and system.

Application software

Programs that allow a user to do specific tasks.

3 examples of application software

Word processor

Photo editor

Video editor

Word processor

A program that allows a user to manipulate word documents.

Photo editor

A program that allows a user to manipulate digital images.

Video editor

A program that allows a user to manipulate videos to produce an edited video.

System software

Programs that allow the hardware to work properly and allow the user to communicate with the system.

3 examples of system software

Utilities

Compiler

Operating system

Utilities

Programs that manage, maintain and control computer resources. E.g: antivirus, backup of files.

Compiler

Program that translates programs that are written in HLL (High level language) into machine code (code understood by the computer)

Operating system

A program that runs in the background of an operating system. It allows input/output operations and the user to communicate with the system.

CPU (Central processing unit)

Part of the computer where commands are interpreted and executed from the hardware and software.

Internal HDD or SSD

Main storage of the computer. Here application software, operating system and files (such as photos and music) is stored.

RAM (Random Access Memory)

Where temporary data is stored while running applications.

ROM (read-only memory)

Information that needs to be permanent are kept here, for example: configuration settings and bootfile. This chip cannot be altered and only be read from.

BIOS (basic input/output system)

It instructs the computer what to do when it is first turned on. Also known as the boot file.

CLI (Command Line Interface)

An interface which requires the user to type in commands to choose options from menus and open software. So the user has to learn a number of commands.

GUI (graphical user interface)

An interface where the user interacts by icons and pictures. For example, launching an application can be replaced by a single icon, rather than typing out lines of code.

Advantages of CLI

Direct communication with computer

Not restricted to predetermined options

Possible to alter configuration settings

Disadvantages of CLI

Requires user to remember commands

Typing takes time anc error-prone

Once a command is entered it is hard to edit

Commands can only be entered in a specific format

Advantages of GUI

A lot more user-friendly

User doesn't have to remember commands

A simple action can be replaced by a single icon rather than having to type out commands.

Disadvantages of GUI

Takes up a lot of memory

Usually requires an operating system

Who uses CLI?

Programmers, analysts and technicians.

Who uses GUI?

People who don't have, or don't need, great information about how computers work. For example: photo editors or gamers.

WIMP

Windows Icons Menus Pointing device

PC/Desktop Advantages to laptop

Better specifications for a given price

Power consumption not critical since it's plugged directly into a wall outlet.

PC/Desktop disadvantages to laptop

Not portable

Since its not portable, if file wanted to be used elsewhere they would need to be copied first.

Laptop advantages to PC

Portable

No trailing wires since all hardware in one piece

Laptop disadvantages to PC

Portable so can be stolen

Battery life

Tablet advantages to laptops

Due to touch-screen technology no external input devices needed

Battery life longer

Tablet disadvantages to laptops

Can be expensive if using data networks all the time.

Typing on a keyboard can be slow and error prone

Smartphones advantages

Small lighweight and extremely portable

Can make calls and browse the internet on the go

Smartphone disadvantages

Small screen so browsing the Internet may not be clear

Web browsing and photography can drain battery.

Smartwatch advantages

More convenient since notifications sent directly to users wrist

Can monitor fitness and health regimes

Smartwatch disadvantages

Rather bulky so can be uncomfortable

Rather unattractive

Mainframe computers

Large computers that take up a lot of room. Usually used by companies that need to process large amounts of data at a time.

AI Biometrics

AI biometrics uses dynamic profiling which uses AI to learn more about a person's biometrics over time.

Low vision enhancement

Uses a headset and a computer. An image is projected into the headset infront of the eyes to bring the image closer.

Night vision enhancement

Amplifies infrared and visible light to allow vision in darkness.

Robotics

Use of robots in manufacturing, drones and surgical procedures.

Quantum cryptography

Use of photons (light) and their physical quantum properties to create a virtually unbreakable system.

Computer assisted translator (CAT)

A language translator that uses software to help improve translation. It uses 2 tools:

Terminology database- which learns new terminology and grows

Translation memories- which automatically inserts known translations

3D holographic imaging

Use of holograph to produce a 3D image.

Uses of holographs

Engineering models

Architecture

Simulations

Virtual reality

Using data goggles, sensor suits and data gloves to give a sense of reality.

Uses of virtual reality

Military

Entertainment

Education