Operating System

An Operating System (OS) is system software that manages computer hardware and software resources. it acts as the interface between users and hardware.

Core Functions

1. Process Management

• Processes & Threads: Basic units of resource allocation and execution.
• Scheduling: FCFS, SJF, Round Robin (RR), etc.
• Synchronization: Mutex, Semaphores, and Deadlock prevention.

2. Memory Management

• Virtual Memory: Allowing programs to use more space than physical RAM.
• Paging & Segmentation: Logical organization and physical mapping of memory.
• Page Replacement: LRU, FIFO, etc.

3. File Systems

• File structures, directory management, and disk scheduling.

4. Device Management

• Drivers and buffer management.

Fundamentals

1. 1 Byte = 8 bits

This relationship is fixed and applies to all computer systems.

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The Operating System is the foundation of all software.