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BCA-Bachelor of Computer Applications
Operating System
Index
- Definition
- Booting
- Need of Operating System 3.1. Resource Management (Sharing the Kitchen) 3.2. Process Management (Keeping a Task List) 3.3. Security (Locking Certain Rooms) 3.4. File Management (Organising the Cupboards) 3.5. Device Management (Talking to Devices)
- Functions of Operating System 4.1. Process Management 4.2. Memory Management 4.3. Device Management 4.4. Secondary Storage Management 4.5. File System Management 4.6. Performance Monitoring 4.7. Error Detection 4.8. Protection and Security 4.9. User Interface (UI) 4.10. Networking
Definition
Operating system is a software that manages and handles hardware and software resources of a computing device such as CPU, memory and files. It performs core functions like process, memory and file management. It acts as an interface between user and hardware. It is the first program that gets loaded into memory through a process called booting. For example โ Linux, Unix, Windows-7,8,10,11, Android, macOS, iOS.
- Booting - Booting is an important process of starting a computer, initializing hardware, and loading the operating system (OS) into memory.
Need of Operating System
The Operating System is Like a House Manager
Imagine This...
You live in a busy house. There's a cook, a cleaner, a guard, and many guests arriving everyday. Someone needs to manage everything โ who uses the kitchen, who sleeps where, who gets inside. That someone is the Operating System.
Why Is This Manager Needed?
1. Sharing the Kitchen (Resource Management)
Only one person can use the stove at a time. The manager decides whose turn it is, so nobody fights and nothing burns. Similarly, the OS decides which app uses the processor and when.
2. Keeping a Task List (Process Management)
The manager writes down every task โ cook breakfast, clean the room, fix the door. They make sure everything gets done in order, nothing is forgotten, and no two people collide doing the same job.
3. Locking Certain Rooms (Security)
Some rooms are private. The manager only gives keys to the right people. The OS does the same โ it protects your personal files from unauthorised programs.
4. Organising the Cupboards (File Management)
Inter-Process Communication (IPC) โ It allows processes to exchange data.
2) Memory Management
Memory management is usually shared by operating systems and application programs. It helps to manage RAM usage. It controls how data is stored and organized in main (primary) memory and secondary storage.
Key activities in Memory Management include:
Allocation and Deallocation โ It assigns and frees memory as needed. Protection โ It prevents processes from interfering with each other's memory. Virtual Memory โ It uses disk space as extra memory to run large programs. Disk Management โ It handles file storage, free space, disk scheduling and backups.
3) Device Management
It controls hardware devices using device drivers. Devices include keyboard, mouse, scanner, printer etc. For example โ When you print a file, the OS sends data to the printer.
4) Secondary Storage Management
The OS manages secondary storage like a pen drive and it handles file storage organization. For example โ Pen drives store data.
5) File System Management
It organizes and controls how data is stored, named and accessed on storage devices. It makes it easy for users to find and use their files. It includes: create, delete, and rename files. For example โ Saving a document in a folder.
6) Performance Monitoring
It tracks system efficiency.
7) Error Detection
It generates error logs, traces and dumps to detect and fix issues.
8) Protection and Security
The mechanisms in an OS are designed to safeguard system resources from unauthorized access or misuse. It ensures authorized users can perform specific actions. It includes: Authentication โ It provides security against malware and data theft. Resource Protection โ It prevents misuse of files, memory or devices. Access Control โ It limits user and process permissions.
9) User Interface (UI)
The OS provides an interface for users to interact with the system.
10) Networking
It is used for exchanging information among different computers that are distributed across various locations.
