Operating Systems Basics
This document provides an overview of basic operating system concepts to help you understand the fundamental components and functions of an OS.
What is an Operating System?
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Types of Operating Systems
- Batch Operating System: Executes batches of jobs without manual intervention.
- Time-Sharing Operating System: Allows multiple users to use the system simultaneously.
- Distributed Operating System: Manages a group of distinct computers and makes them appear to be a single computer.
- Network Operating System: Provides services to computers connected to a network.
- Real-Time Operating System: Responds to input instantly.
Functions of an Operating System
- Process Management: Handles the creation, scheduling, and termination of processes.
- Memory Management: Manages the allocation and deallocation of memory space.
- File System Management: Controls the creation, deletion, and access of files.
- Device Management: Manages device communication via their respective drivers.
- Security and Access Control: Protects data and resources from unauthorized access.
Process Management
- Process: A program in execution.
- Thread: The smallest unit of a process.
- Scheduling: Determines which process runs at a given time.
- Inter-Process Communication (IPC): Mechanisms for processes to communicate and synchronize.
Memory Management
- RAM: Random Access Memory, volatile memory used for temporary storage.
- Virtual Memory: Extends physical memory onto disk storage.
- Paging: Divides memory into fixed-size pages.
- Segmentation: Divides memory into variable-sized segments.
File System Management
- File: A collection of related data.
- Directory: A container for files.
- File Permissions: Controls who can read, write, or execute a file.
- File System Types: Examples include NTFS, FAT32, ext4.
Device Management
- Device Driver: Software that controls a hardware device.
- I/O Operations: Input and output operations for device communication.
- Buffering: Temporary storage for data transfer.
Security and Access Control
- Authentication: Verifying the identity of a user.
- Authorization: Granting access to resources based on identity.
- Encryption: Protecting data by converting it into a secure format.
User Interface
- Command-Line Interface (CLI): Text-based interface for interacting with the OS.
- Graphical User Interface (GUI): Visual interface with graphical elements.
These concepts provide a foundational understanding of operating systems and their essential functions.