SYSTEMS

operating system

an intermediary between the computer hardware and the user. It prevents the user from directly accessing the hardware and manages all system resources.

It provides an environment in which a user can execute programs conveniently and efficiently.

True

Operating system (OS) is a program that runs at all times on a computer.

operating systems

It assigns resources such as memory, processors, and input/output devices to processes that need them.

Control Flow

Functions of Operating System

• process management

• memory management

• file management

• device management

• command interpreter system

• network management

• security management

• secondary storage management

Examples of OS

• windows

• macOS

• Linux

• ChromeOS

• Android

• IOS

• UNIX

• BSD

True

Every general-purpose computer consists of hardware, an operating system, system programs and application programs.

CPU, ALU, memory, I/O devices, peripheral devices and storage devices

The hardware includes ______________

compilers, loaders, editors and the OS itself.

The system programs include __________________

The application programs

user-level software that perform specific tasks

always

An operating system is _____ running in the background to manage and coordinate the use of hardware resources among system and application programs for multiple users.

An OS provides user interaction mainly through:

• CLI (Command-Line Interface) → e.g., Bash, PowerShell

• GUI (Graphical User Interface) → e.g., Windows desktop, macOS Finder

💡 Remember: The OS itself is not just a user interface; it provides interfaces for users to interact with the system.

What are the main ways an Operating System (OS) provides an interface for user interaction?

• User Convenience – Provide an intuitive, user-friendly interface.

• Program Execution – Provide the environment and services needed to run software.

• Resource Management – Manage and allocate CPU, memory, storage, and I/O devices fairly.

• Security – Protect data and prevent unauthorized access.

• Efficient Resource Utilization – Maximize hardware performance and utilization.

• Reliability – Handle errors gracefully for stable, continuous operation

What are the main goals of an Operating System (OS)?

• Windows → Developed by Microsoft; personal computing, business, gaming.

• macOS → Developed by Apple; creative industries, personal computing, professional environments.

• Linux → Started by Linus Torvalds and maintained by the open-source community; servers, data centers, programming, and tech enthusiasts.

What are the 3 common Operating Systems (OS) and what are they used for?

1. Price → Free (Linux) vs. paid (Windows, macOS).

2. Accessibility → Choose an OS that is intuitive and easy for you to use.

3. Compatibility → Make sure it supports the applications you need.

4. Security → Consider security features, updates, configuration, and safe usage.

What are the factors to consider when choosing an Operating System?

1940s–50s → No OS → GM-NAA I/O (1956)
↓
1960s → Multiprogramming & Timesharing
↓
1970s → Unix & Personal Computers
↓
1980s → GUI & Networking
↓
1990s → Linux & Advanced GUIs
↓
2000s–Present → Mobile, Cloud & Virtualization
↓
Ongoing → AI Integration 🤖

What is the OS history timeline?

1940s–1950s: Early Beginnings

Computers operated without OSs; programs were manually loaded and run one at a time.

GM-NAA I/O (1956)

The first operating system; a batch processing system that automated job handling.

1960s: Multiprogramming

Introduction of multiprogramming to utilize CPU efficiently. Timesharing systems, like CTSS (1961) and Multics (1969), allowed multiple users to interact with a single system.

Timesharing

Allowed multiple users to interact with a single computer system.

1970

Unix and Personal Computers

Unix (1971)

revolutionized OS design with simplicity, portability, and multitasking.

1980s

Graphical User Interfaces became popular, making computers easier to interact with.

Apple Macintosh (1984)

Popularized GUI-based personal computing.

Microsoft Windows (1985)

A GUI-based OS that became widely adopted.

1990s

Linux and Advanced GUIs Linux (1991) introduced open-source development. Windows and Mac OS refined GUIs and gained widespread adoption.

2000s-Present

Mobility and Cloud

Mobile OSs like iOS (2007) and Android (2008) dominate. Cloud-based

and virtualization technologies reshape computing, with OSs like

Windows Server and Linux driving innovation.

ongoing

AI integration