Operating Systems Overview
Overview
An operating system is the main software that allows a computer to work, managing hardware and letting the user run programs, save files, connect to the internet, and manage accounts.
Key concepts
- Process management
- Memory management
- File management
- Device management
- User management
- Security
How it works
An operating system, or OS, is the main software that allows a computer to work. It manages the hardware — CPU, RAM, storage, keyboard, monitor, network adapter — and lets the user run programs, save files, connect to the internet, and manage accounts.
The three main operating systems IT professionals should understand are Windows, Linux, and macOS. Each works differently and has its own tools, file systems, command line, and security features.
Main Responsibilities
Process Management
The OS manages the programs currently running on the computer, deciding which program gets CPU time and preventing one program from taking all system resources.
Memory Management
The OS assigns RAM to running programs. When you open a browser, game, or document, the OS gives it memory so it can run properly.
File Management
The OS organizes files and folders on storage devices, letting users save, open, copy, move, and delete files.
Device Management
The OS communicates with hardware devices such as printers, keyboards, graphics cards, storage drives, Wi-Fi adapters, and Bluetooth devices.
User Management
The OS creates and manages user accounts. Different users can have different files, settings, and levels of access.
Security
The OS helps protect the system through passwords, permissions, firewalls, updates, encryption, and antivirus software.