An operating system is a main program on computer, that governs all other applications. It allows you to use browsers, play games, print documents, launch your favorite program.
Most common Operation Systems:
Windows (desktops mostly)
Mac OS (laptops mostly)
Android (cell phones)
Linux (hard-code users & programmers)
How Operation System work. Basics
Computer CPU knows how to execute commands. But it needs someone to tell him what command to execute. It is the job of Operation System (OS).
Whenever you power your computer, it reads first bytes on your Disk Drive, where it expects to see commands that will start Operation System.
Components of Operation System
OS Kernel
main part of OS, it facilitates interactions between hardware and software components and performs task scheduling
Drivers - small programs that are responsible for interaction with different hardware: keyboard, printer, usb drive etc
User Interface - responsible for displaying all those windows, buttons and so on. Based on DirectX/OpenGL from once side, and on some UI Framework from other side (WPF, Windows Forms, WinAPI, HTML, etc)
Please use below materials for deep dive into the topic
An Operating System (OS) is an interface between a computer user and computer hardware. An operating system is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.
An operating system (OS) is software that performs the task required to keep the system running, and provides the main interface for the user. In essence, the operating system enables the computer’s hardware to communicate with and control the computer’s software, while providing the user with a way to interact with both.
How OS manages to run multiple application simultaneously?
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0♡
Q:
What is the main goals of OS?
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"Enforce security rules for all applications and users and restrict access to files depending on permissions"
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0♡
Q:
Do you need OS to start a program?
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Add question
Do you know that ...?
0♡- Many OSs can "trick" programs into using memory scattered around the hard disk and RAM as if it is one continuous chunk of memory, called virtual memory.
1♡- Normally every thread is executed during 20ms
Hence, only about 50 threads could execute during a second, while many processes contains hundreds of threads. To manage this chaos, OS provides priority level to all programs and ensures that every program has some execution time
0♡- There are more than a hundred of different OSs
*nix-based family, mobile OSs, Windows of all kinds, OSs for embded devices, OSs for specific devices, etc
