CET 1000 Operating System

Definition of an OS

An operating system (OS) is software that manages computer hardware and software resources and provides common services for computer programs, acting as an intermediary between users and the computer hardware.

What are the functions of the an OS

• Controls access to hardware resources

• ensures fair allocation of system resources

• provides security and protection

• creates a UI

What is hardware

provides basic computing resources

examples of hardware

Central Processing Unit, Memory, Input/Output devices

what is a system and application program

the ways in which system resources are used to solve computing problem of a user

examples of system and application program

word processor, compilers, web browser

What are the key components of an OS

• Kernel

• Shell

• System Programs

• Device Drivers

Function of a Kernel

• core component

• manages operations

• provides interface between hardware and software

Function of the Shell

user interface that allows you to interact with the os thru CLI and GUI

What are the device drivers

• software components

• allows OS to communicate with hardware devices

Functions of the OS

• Process Management

• File system Management 

• Device Management

• Memory Management

• Security and Access Control

What is Process Management

• ensures efficient CPU utilisation

• handles creation scheduling and coordination of processes

• ensures each process uses the cpu and has access to required resources

Memory management

allocates and deallocates memory processes efficiently

track memory usage

minimises fragmentation

File system management

provide a structured way to store organise data on devices

what are some common file systems

HFS - for macOS

NTFS - for windows

What are the types of device management

• dedicated ( assigned to one task at a time. eg printer)

• shared used by multiple processes (eg disk drives)

• virtual (dedicated devices are converted to shared) by spooling

Definition for spooling

data is stored in a queue in a secondary memory whilst the computer focuses on other tasks whilst a slower device like a printer processes data at its own pace

All types of OS security

• Authentication and Authorisation

• Access Control 

• Encryption 

• Updates and Patches 

Explain Authentication and Authorisation OS security

Controls who can access the system and what resources they can use

Explain Access Control

Restricts access to certain resources and operations on a computer

Explain Encryption

OS encrypts files and secures them from unauthorised access

Explain Updates and Patches 

strengthens system against threats, regular updates address vulnerabilities