Operating systems basics

Hello students, welcome to Kwickprep. When you press the power button, who wakes up the computer and opens your apps? It is the operating system. Today we will learn what an operating system is, what it does, and its common types.

Before we begin, two basic terms. Hardware means the physical parts you can touch, like the keyboard, monitor and CPU. Software means the programs that tell the hardware what to do. Software is of two main types, system software and application software.

Let us compare the two types. System software runs and controls the computer itself, and the operating system is the most important system software. Application software helps the user do a task, like typing a letter in Word or browsing the internet in Chrome.

Now the main idea. An operating system, or OS, is system software that manages the whole computer. It acts as a link between you, your apps and the hardware. It is the first main program to load when the computer starts, and this starting process is called booting.

Here is how the layers connect, from top to bottom. The user gives a command, like clicking print. The application software receives that command. The operating system passes it to the right hardware, such as the printer. The hardware does the job. Then the result reaches you.

An operating system does five main jobs. It manages the processor and memory, so many apps can run together. It manages files and folders on the storage. It controls input and output devices, like the printer and the mouse. It gives us a user interface to talk to the computer. And it provides security, like passwords and user accounts.

The user interface is how we talk to the computer, and there are two main kinds. A command line interface, or CLI, needs you to type text commands, like in MS-DOS or the Linux Terminal. A graphical user interface, or GUI, lets you click icons, windows and menus with a mouse or a finger. Most people today use a GUI.

Let us meet common operating systems. Windows is used on most computers and is made by Microsoft. macOS runs on Apple computers. Linux, with versions like Ubuntu, is open source, which means its code is free for anyone to see and change. Android runs on most phones in India and comes from Google. And iOS runs on iPhones, made by Apple.

Operating systems are also grouped by who owns them. Open source software shares its code freely, so anyone can study and improve it. Proprietary software is owned by a company, and its code is kept closed. For example, Linux is open source, while Windows and macOS are proprietary.

Now some basic steps you must know. Press the power button, and the operating system boots. Log in with your user name and password. Before switching off, always save your work and close apps. On Windows, click Start, then Power, then Shut down, instead of pulling the plug.

Pause and think. Your phone runs WhatsApp and a camera app. Which one is the operating system? Neither of them, since both are application software. The operating system is Android or iOS, which runs underneath them both.

Let us revise what we learned today. An operating system is system software that manages the computer. It links the user, the apps and the hardware. It manages memory, files, devices and security. A CLI uses typed commands, and a GUI uses icons and menus. And common examples are Windows, macOS, Linux, Android and iOS.