Systems Software

Operating system

An essential piece of software that controls the operations of the computer

Applications

Programs that are called up by the operating system that perform specific tasks

Basic Input/Output (BIOS) System

Controls the computer when it is first switched on, tests the system hardware and loads the operating system.

Operating System Examples

Windows, iOS, Android and Linux

Functions of an operating system

Provides the interface between the user and computer, manages how data is received from input devices, manages how computer interacts with other computers, controls access and security

O/S Layer 1

User interacts with an application program

O/S Layer 2

Application program carries out specific tasks

O/S Layer 3

Application layer communicates with the operating system

O/S Layer 4

Operating system controls how the application interacts with the computer’s hardware

User Interface

Means by which the user provides an input to the computer and the computer conveys and output to the user through use of input/output devices

Graphical User Interface(GUI)

Provides visual representations of the files and devices on a computer and allows you to use these resources by clicking, dragging and touching their graphical representation using WIMP

Windows-Icon-Menu-Pointer (WIMP)

Programs and files are represented by icons, and run in movable windows. User interaction is through a moving pointer via a mouse, keyboard or touchscreen

Command Line Interface

An interface predating GUIs where the user has to type in commands for the operating system and receives feedback in form of text.

Peripherals

External devices that are connected to a computer

Device Manager

Keeps track of which devices are connected to which ports and allows applications to read data from and send data to each peripheral

Memory manager

Controls the allocation of the computer’s primary memory (RAM) to each process that is running

File Manager

Keeps track of where specific files and folders are physically located in secondary storage

User Manager

Keeps track of which users can access the system and which are currently logged in

User Access Control

A security measure that prevents a standard user from installing applications and changing the master password

Anti-virus software

Scans and removes malicious files

Encryption software

Uses an algorithm to scramble a file according to the key which is needed to decrypt the file back to its original form

Firewall

Prevents unwanted access to a computer over a network

Spyware detector

Blocks and removes programs designed to collect personal information and transmit it to another user

Backup programs

Configured to back up sensitive data at specific times and also compresses data so it takes up less storage space

Full backup

Where all specified data is backed up

Incremental backup

Where only new files or ones that have changed since the last backup are saved which saves time

Resource management

How the operating system controls and coordinates the computer’s hardware resources such as CPU time, memory (RAM), secondary storage and input/output devices

File management

How the operating system organises and keeps track of files on storage devices like hard drives and ensures they can be created, accessed or modified when needed

Firmware

Software embedded into into hardware devices

Ransomware

Malicious software(malware) that threatens to publish or block access to data or a computer system by encrypting it until the victim pays a ransom fee to the attacker

Measures to reduce a cyberattack

Anti-virus software, security systems such as firewalls or VPNs and encryption