Types and components of computer systems

Hardware

The physical components which make up the computer system.
Each item of hardware have their specific roles in a computer system.
Hardware components can either be internal or external.

Central Processing Unit (CPU)

It is the device that carries out calculations to complete software instructions. the Control Unit (CU), the Arithmetic Logic Unit (ALU), and the Immediate Access Store (Cache).

Motherboard

The circuit board which is connects to main components of the computer system.

Memory

Any data or instructions that are to be processed by the CPU must be placed into main memory.

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Graphic Video Cards

A device that attaches to the motherboard to enable the computer to process and display graphics.

Sound Card

A device that attaches to the motherboard to enable the computer to input, process, and deliver sound.

Internal Hard Disk

A hardware device that's used to store information like software and files. The capacity of hard drive ranges from GB to Tera Bytes.

Network Card

Provides the computer with a network (internet connection) either through wireless signals or a physical cable connection.

Optical Disk Drive

Allows for optical disks (CD/DVD/Blu-Ray) to run on the computer. Also some optical disk drives are able to write “burn” data onto discs.

Power Supply

Connected to main power sources to give power to the computer system. The power supply connects to all the main components of the computer system including the motherboard, hard drive, optical drives etc.

Input Hardware Devices

Devices that input data into a Computer. Examples: Mouse, Keyboard, Microphone.

Output Hardware Devices

Devices that output data from a computer. Examples: Monitor, Speakers, Printers.

External Storage Devices

Provides external storage or backup solutions. Example: External Hard drive.

Software

A collection of instructions that can be ‘run’ on a computer. These instructions tell the computer what to do. Software is not a physical thing, it is just a bunch of codes.

Application Software

Designed to allow users to complete specific tasks such as writing a letter, browsing the internet, or manipulating data. Examples: Word Processor, Spreadsheet, Databases.

System Software

Normally involved in the running of the computer, providing user interfaces, allowing hardware to work, and maintaining performance. Examples: Operating Systems, Device Drivers, Utilities.

Word Processing

Used to prepare reports, school essays etc. Features include formatting tools, spell check, and page layout.

Spreadsheet

Use to create to organise and manipulate numeric data using formulas (Sum, Max, Min, etc.) and creating graphs.

Database

Used to insert and organise data using fields and records. Used to run queries and create reports.

Photo Editing

Used to edit digital images to either touch up or to apply various formatting techniques (Contrast, Layers, Filters).

Graphics Manipulation

Used to create and edit bitmap (pixels) and vector (lines, curves) graphics.

Video Editing

Used to edit and format video using tools like split/trim, transitions, and inserting audio.

Apps (Phone Applications)

Software which runs on mobile phones for games, streaming, social media, communication, GPS, etc.

Measuring and Control Software

Responsible for changing physical conditions in an environment. Measuring uses sensors

Control software compares readings to pre-set levels to decide on an output.

Device Drivers

program that allows the Operating System to communicate with a specific piece of hardware including printers, sound, graphics and network cards.

Linkers

Combines object files produced by a compiler into a single program.

Operating Systems

Manages computers functions including hardware devices (input/output). Also provides users with a GUI interface.

Compiler

Translates a program written in a specific language which can be understood by the computer.

Utilities

Help to manage and maintain computer resources and performance by running specific tasks.

Section 1.2: The Main Components of Computer Systems
CPU Speed

Measured in Gigahertz (GHz). A 1 GHz CPU can carry out 1 billion instructions per second!

Cache

The fastest type of Memory. Located between the processor and the RAM. It holds onto commonly used data and automatically transfers the next set of data from the RAM.

RAM (Random Access Memory)

Temporarily stores the instructions that the computer is running whilst the data is being processed. It is volatile (data is lost when turned off). Main memory (RAM) is directly accessible by the CPU

Backing storage is not.

ROM (Read Only Memory)

Built-in memory that cannot be changed. Holds ‘boot up’ instructions. It is non-volatile (data is not lost when turned off).

Peripheral Devices

The general name for extra devices connected to a computer, categorized into input, output, and storage devices.

Backing Storage (Secondary Storage)

Non-volatile storage used to store data for a long time (read from and written to). Used for making copies of original files. Main memory (RAM) is directly accessible by the CPU

Backing storage is not.

Section 1.3: Operating Systems
Main Roles of an Operating System

Provides user interface, provides security, allows users to load/run applications, manages memory, organizes files, and manages hardware devices.

GUI (Graphical User Interface)

An interface built around graphics using WIMP: Windows, Icons, Menus, and Pointers. Easy to use due to visual clues.

Post GUI

Allows the use of touch screen technology, pinching, scrolling, and expanding.

CLI (Command Line Interface)

Requires the user to enter command prompts to interact with the computer. Normally used by expert users and is not restricted to predetermined options.

Section 1.4: Types of Computer
Desktop/Personal Computer

Computer small enough to fit on desks. Always connected to mains, higher specifications, but not portable and takes up space.

Laptop Computer

All components (monitor, keyboard, etc.) together on a single device. Portable and can connect wirelessly, but has limited battery life and is difficult to upgrade.

Tablet Computer

Similar to smartphones with internet via wireless/3G/4G. Uses touch screen and has longer battery life than a phone, but has limited memory and can be difficult for typing.

Smartphone

Small device used for calls, messages, and running multiple apps (email, social media, GPS). Extremely portable but has small screens and short battery life.

Phablet

a hybrid device that combines the functionality of a smartphone with the larger screen size of a tablet

Section 1.5: Emerging Technologies
Artificial Intelligence (AI)

Computer systems that can simulate human intelligence and make decisions typically made by a human.

Biometrics Authentication

Form of identification recognizing unique body parts (Fingerprints, Eye/Iris recognition, Facial/Voice recognition) to improve security.

Vision Enhancement

Video technology projected through a lens that brings distant objects closer or amplifies infrared light for night vision.

Robotics

Used in manufacturing for labor-intensive jobs. Can work in extreme conditions and complete tasks with precision (e.g., welding, assembly, surgery).

Quantum Cryptography

Technology that allows for securing communications whilst online, commonly used in online shopping and banking.

Computer-assisted Translation

Software (like Google Translate) that translates typed or spoken information into a selected language.

3D and Holographic Imaging

Technology that allows 3D images to be produced using split laser beams (object beam and reference beam).

Virtual Reality (VR)

Artificial environment created with software. Uses head-mounted displays for training, education, games, and construction.