What a computer does and how to start

A computer is a machine that follows instructions you give it. You give those instructions by moving a mouse, pressing keys on a keyboard, or touching a screen. The computer then does the task — it might show you a picture, let you type a letter, play a video, or connect you to the internet.

To start, press the power button. On a desktop computer, this is usually a large button on the front or back of the tower. On a laptop, it is often a small button near the keyboard. The screen will light up and show words or images. Wait 30 seconds to two minutes for the computer to fully load. You will see a screen asking you to log in or showing a home screen with icons — small pictures that represent programs.

If you have never used the computer before, someone may have already set up a user account for you. If not, the computer will walk you through creating one. You will choose a name and a password (a secret code only you know). Write your password down in a safe place until you remember it.

Key Takeaways

  • The mouse moves a pointer on the screen; clicking the left button selects things, and the right button shows extra options.
  • The keyboard lets you type letters, numbers, and symbols; the spacebar, Enter, and arrow keys do specific jobs.
  • Programs are applications that do one task — email, writing, video, web browsing — and you open them by double-clicking their icon.
  • The internet connects your computer to websites and other computers; you access it through a web browser like Chrome or Edge.
  • Saving your work means storing it on the computer so you can find it again later; use File > Save or press Ctrl+S.

Using the mouse and keyboard

The mouse is a small device you hold in your hand. When you move it on a flat surface, a pointer (usually an arrow) moves on the screen in the same direction. The mouse has buttons on top. The left button is what you use most — click it once to select something, or double-click (click twice quickly) to open a program or file. The right button shows a menu of extra choices for whatever you clicked on.

The keyboard has keys arranged like a typewriter. Letter keys (A through Z) let you type words. Number keys (0 through 9) let you type numbers. The spacebar at the bottom adds a space between words. The Enter key (also called Return) moves to a new line or confirms an action. The arrow keys move the cursor (a blinking line) up, down, left, or right. The Backspace key deletes the letter before the cursor. The Delete key deletes the letter after the cursor.

Some keys do special jobs. Shift makes letters uppercase and changes number keys to symbols like ! and @. Ctrl (Control) is used with other keys — for example, Ctrl+C copies something, and Ctrl+V pastes it. Alt and Windows keys also combine with other keys to perform tasks. You do not need to memorize all of these right away. You will learn them as you use the computer.

Opening and closing programs

A program (also called an process or app) is software that does one specific job. Microsoft Word lets you write and format documents. Google Chrome lets you browse the internet. Outlook lets you send and receive email. Spotify plays music. Each program has its own icon — a small picture — usually shown on the desktop (the main screen you see when the computer starts) or in a menu.

To open a program, find its icon and double-click it with the left mouse button. The program will load, which takes a few seconds to a minute. Once it opens, you can start using it. To close a program, look for an X button in the top right corner of the window and click it. Or use the keyboard shortcut Alt+F4. If the program asks whether you want to save your work, click Yes if you want to keep what you typed or created, or No if you want to discard it.

If a program stops responding or freezes, you can force it to close. Press Ctrl+Alt+Delete, then click Task Manager. Find the program that is not responding, click it, and click End Task. This will close the program without saving, so use this only when the program will not respond to normal closing.

Understanding files and folders

A file is a single piece of work — a letter you typed, a photo, a video, or a spreadsheet. A folder is a container that holds files, the same way a real folder holds papers. Folders can also hold other folders inside them, creating an organized structure.

When you save your work, you choose where to put it. Most computers have a folder called Documents where you should save your writing. There is usually a Pictures folder for photos and a Downloads folder for files you get from the internet. You can create new folders to organize your files by topic or date. Right-click in an empty area, select New > Folder, and type a name.

To find a file you saved, open File Explorer (on Windows) or Finder (on Mac). This shows you all your folders and files. Navigate to the folder where you saved it, then double-click the file to open it. If you cannot remember where you saved it, use the search box at the top of File Explorer and type the file name or part of it.

Connecting to the internet and using a web browser

The internet connects your computer to websites and other computers around the world. To use it, your computer must be connected to the internet through Wi-Fi (wireless) or an ethernet cable (wired). Most computers show a Wi-Fi icon in the bottom right corner (Windows) or top right corner (Mac). Click it to see available networks, select yours, and enter the password if you have one.

A web browser is a program that lets you view websites. Common browsers are Google Chrome, Microsoft Edge, Firefox, and Safari. Open your browser by double-clicking its icon. You will see a search box at the top. Type what you want to find — for example, "weather" or "recipe for chicken soup" — and press Enter. The browser will show you a list of websites related to what you searched for. Click on one to visit it.

Each website has a web address (called a URL) that starts with http:// or https://. If you know the exact address, you can type it directly into the search box. For example, typing "google.com" takes you to Google's website. Use the back arrow button to return to the previous website, and the forward arrow to go ahead. Bookmark websites you visit often by pressing Ctrl+D or clicking the star icon — this saves them in a list you can access quickly.

Saving and finding your work

When you create something — a letter, a spreadsheet, a photo edit — you must save it so the computer stores it and you can find it later. If you close a program without saving, your work is lost. Most programs remind you to save before closing.

To save, use the keyboard shortcut Ctrl+S, or go to the File menu and click Save. The first time you save, the computer asks you to name the file and choose where to put it. Give it a clear name like "Tax Return 2024" or "Birthday Party Photos". Choose a folder like Documents or Pictures. Click Save. The next time you save the same file, Ctrl+S updates it without asking questions.

To find a file later, open File Explorer or Finder and navigate to the folder where you saved it. Or use the search function — press Ctrl+F on Windows or Command+Space on Mac, type the file name, and press Enter. The computer will show you where the file is located.

Staying safe while using a computer

Computers can be damaged by viruses (malicious software) and by people trying to steal your information. Protect yourself by using a strong password — one that mixes uppercase letters, lowercase letters, numbers, and symbols, and is at least 12 characters long. Do not use your birthday, your name, or straightforward words like "password123".

Do not click links in emails from people you do not know, and do not read files from untrusted websites. If an email looks suspicious — asking for your password or banking information — delete it. Real companies never ask for passwords by email.

Keep your computer updated. When the computer or a program offers an update, install it. Updates fix security holes that hackers can use. Use antivirus software — Windows includes Windows Defender, and Mac includes built-in protection. These programs scan for and remove malicious software.

Back up your important files regularly. This means making a copy and storing it somewhere safe, like an external hard drive or cloud storage (online storage you access through the internet). If your computer breaks or gets infected, your files are still safe.

Frequently Asked Questions

What is the difference between a laptop and a desktop computer?

A desktop computer has a separate monitor (screen), keyboard, and mouse, and sits in one place. A laptop is all-in-one and portable — the screen, keyboard, and touchpad (which works like a mouse) are built in. Laptops run on batteries and can be used anywhere. Desktops need to be plugged in but are usually less expensive.

How do I make the text on the screen bigger if it is hard to read?

On Windows, right-click on the desktop, select Display Settings, and look for a Scale option. Move the slider to the right to make everything larger. On Mac, go to System Preferences > Displays and adjust the Resolution. You can also zoom in on a single window by pressing Ctrl and the plus key (+) together, or Cmd and plus on Mac.

What should I do if my computer is running very slowly?

Close programs you are not using. Restart the computer by clicking the Start menu, selecting Shut Down, waiting for it to turn off, and pressing the power button again. Delete files you no longer need. Run a virus scan using your antivirus software. If it is still slow, the hard drive may be full or the computer may be old — consider having a technician check it.

Can I undo something I accidentally deleted or changed?

Yes. Press Ctrl+Z to undo your last action. You can press it multiple times to undo several actions in a row. This works in most programs. If you have already closed the program, the undo may not work — this is another reason to save your work often and keep backups.

How do I turn off the computer safely?

Click the Start menu (Windows) or the Apple menu (Mac), then select Shut Down. Wait for the screen to go black. Do not hold down the power button or unplug the computer while it is shutting down — this can damage files. If you are not using the computer for a while but want to keep it on, you can put it to sleep instead, which uses less power.