What is a computer?

Parts of a desktop computer

A desktop computer comes in multiple pieces. The main ones are:

• The computer case, which contains the brains of the desktop computer. All the other parts of desktop computer connect to the case.
• The screen also called a monitor, which lets you see what’s happening on the computer. Some desktop computers combine the screen with the computer case, or box.
• The keyboard that lets you type text, numbers and symbols into the computer.
• The mouse, which lets you point at, select and move items you see on the screen.

How to turn a desktop computer on and off

To turn a desktop computer on or off, you need to press the power button. Look for a button with a symbol that looks like a circle with a line through it. Don’t worry if it takes a minute to start. That’s normal.

Using a keyboard

Desktop computers, laptops and some tablets use keyboards for typing in text:

• Most English language keyboards use the same layout for letters. It’s called QWERTY, from six of the keyboard letters.
• Press the key with the letter on it, to type that letter.
• Use the long Space bar to make the spaces between words.
• Press the Caps lock key to type capital letters. Press it again to go back to lowercase.
• You can also hold down the Shift key while typing a letter to make just that letter a capital.
• Hold down the Shift key to type the second symbol marked on the other half of some keys, such as Shift+8 for * and Shift+/ for ?.
• Press Enter (called Return on some keyboards) to end a line and start a new line.
• Press Backspace to delete the last letter you typed.

Using a mouse

Use the mouse to point to things you see on the screen. The position of the mouse is represented on the screen by the mouse pointer, which is sometimes called a cursor. Here are some tips for using a mouse:

• Slide the mouse in the direction you want the pointer to go.
• Click on the left mouse button to activate the object you’re pointing at. This could be a button, a website link, the play control for a video, and much more.
• Click on the right mouse button to see options related to the object you’re pointing at. These options will appear as a menu.
• Use the wheel in the middle of the mouse to scroll a document up and down.
• Double-click on an icon, using the left mouse button, to start an app.
• The mouse pointer on the screen will sometimes change to show you that something can be interacted with. For example, if you put the mouse pointer over text that works as an internet link, the mouse pointer may turn from an arrow into a pointing finger.
• Try not to squeeze or push down on the mouse. Hold it loosely in your hand and move it smoothly on your table surface. If you get to the edge of the table, lift the mouse and bring it back to the middle of the table: the mouse pointer won’t move if the mouse isn’t touching the table.

How to use your desktop computer safely

A desktop computer is designed to be comfortable to use, but there are some things to know to use it safely, especially for long periods of time.

Install antivirus software before accessing the internet. This will help to protect your computer from malicious programs that may be present on some websites. Learn more in our Using antivirus software course.

Sit in an ergonomic chair with your back straight and at a height that allows your thighs to be parallel to the floor. Position the screen at eye height and close enough that you don’t have to strain your eyes to see what’s on the screen.

How to adjust the screen

The computer’s screen, also called the monitor, can be adjusted to suit your preferences for:

• Brightness
• Contrast
• Volume (if your screen has built-in speakers)
• Input (usually this is set to show a signal from your computer)
• Picture mode (this adjusts colour, brightness, and contrast all at once, to suit for example games, movies, or productivity).

Controls for these settings are usually found under the screen, or on the back near the bottom. When you activate a control, an on-screen display will appear to show you which settings you are adjusting.