💻 What is an Operating System (OS)?
An Operating System (OS) is a software layer that acts as an intermediary between the user and the computer hardware.
🔧 Imagine this:
You’re using a computer. You click on a browser, it opens. You download a file, it gets saved. But how does all of this happen under the hood?
That’s where the Operating System comes in.
🧠 Think of the OS as the brain of the computer that does five key things:
| Component | What it does |
|---|---|
| 🧩 Resource Manager | Manages CPU, memory, disk, and input/output devices |
| 🎛 Process Manager | Controls which program runs, and when |
| 📂 File Manager | Organizes how data is stored and retrieved on disk |
| 🧠 Memory Manager | Decides who gets how much memory, and ensures safety |
| 🔌 Device Manager | Talks to hardware like keyboard, mouse, printer, etc. |
🔑 Key Responsibilities:
-
Program Execution
Runs your apps (like a browser or game) and handles switching between them. -
Memory Management
Allocates RAM efficiently so apps don’t overwrite each other. -
Process Scheduling
Decides which app gets the CPU, especially when many are running at once. -
File System Management
Lets you save, delete, read, and organize files. -
Security & Access Control
Protects data and ensures that one program can’t mess with another. -
User Interface
Provides a way for you to interact with the system (like CLI or GUI).
📱 Real World Examples:
| Device | Operating System |
|---|---|
| PC / Laptop | Windows, macOS, Linux |
| Mobile | Android, iOS |
| Servers | Ubuntu Server, Red Hat, CentOS |
| Embedded Systems | RTOS, FreeRTOS, VxWorks |
🔍 In Interview Terms:
If asked, “What is an Operating System?”
You can say:
An Operating System is system software that manages computer hardware and software resources, and provides services for computer programs. It acts as a bridge between users and hardware to ensure efficient and secure operation of the system.