What is Operating System?

An Operating System (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. It acts as an intermediary between users and the computer hardware, enabling interaction through a user interface (UI) or command line.

Key Functions of an Operating System:

1. Process Management – Handles the execution of multiple processes, including multitasking, scheduling, and synchronization.
2. Memory Management – Allocates and deallocates memory for programs, ensuring efficient usage (RAM, virtual memory).
3. File System Management – Manages files on storage devices (HDD, SSD) with operations like create, read, write, and delete.
4. Device Management – Controls hardware devices via drivers (keyboard, mouse, printer, etc.).
5. User Interface (UI) – Provides a way for users to interact (Graphical UI like Windows or command-line like Linux).
6. Security & Access Control – Protects data through authentication, permissions, and encryption.
7. Networking – Enables communication between computers over networks (Wi-Fi, Ethernet).
8. Error Handling – Detects and manages system errors to prevent crashes.

Types of Operating Systems:

1. Single-User OS (e.g., Windows, macOS) – Supports one user at a time.
2. Multi-User OS (e.g., Linux, UNIX) – Allows multiple users simultaneously.
3. Real-Time OS (RTOS) – Used in time-critical systems (e.g., robotics, medical devices).
4. Embedded OS – Runs on embedded systems (e.g., Android on smartphones, IoT devices).
5. Distributed OS – Manages a group of networked computers as a single system.
6. Batch Processing OS – Executes jobs in batches (older systems like IBM’s OS/360).

Examples of Popular Operating Systems:

• Windows (Windows 10, 11) – By Microsoft, widely used in PCs.
• macOS – Apple’s OS for MacBooks and iMacs.
• Linux (Ubuntu, Fedora) – Open-source, used in servers and development.
• Android – Google’s OS for mobile devices.
• iOS – Apple’s OS for iPhones and iPads.

Importance of an OS:

• Enables users to run applications (web browsers, games, office software).
• Manages hardware efficiently.
• Provides security and stability.