Computer Basics: What is a Computer?
What is a computer?
A computer is an electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data. You may already know that you can use a computer to type documents, send email, play games, and browse the Web. You can also use it to edit or create spreadsheets, presentations, and even video
Hardware vs. software
Before we talk about different types of computers, let's talk about two things all computers have in common: hardware and software.
Hardware is any part of your computer that has a physical structure, such as the keyboard or mouse. It also includes all of the computer's internal parts, which you can see in the image below.
viewing hardware
Software is any set of instructions that tells the hardware what to do and how to do it. Examples of software include web browsers, games, and word processors.
viewing software
Everything you do on your computer will rely on both hardware and software. For example, right now you may be viewing this lesson in a web browser (software) and using your mouse (hardware) to click from page to page. As you learn about different types of computers, ask yourself about the differences in their hardware. As you progress through this tutorial, you'll see that different types of computers also often use different types of software.
What are the different types of computers?
When most people hear the word computer, they think of a personal computer such as a desktop or laptop. However, computers come in many shapes and sizes, and they perform many different functions in our daily lives. When you withdraw cash from an ATM, scan groceries at the store, or use a calculator, you're using a type of computer.
viewing a variety of computers
Desktop computers
showing a desktop computer
Many people use desktop computers at work, home, and school. Desktop computers are designed to be placed on a desk, and they're typically made up of a few different parts, including the computer case, monitor, keyboard, and mouse.
Laptop computers
showing a laptop computer
The second type of computer you may be familiar with is a laptop computer, commonly called a laptop. Laptops are battery-powered computers that are more portable than desktops, allowing you to use them almost anywhere.
Tablet computers
showing a tablet computer
Tablet computers—or tablets—are handheld computers that are even more portable than laptops. Instead of a keyboard and mouse, tablets use a touch-sensitive screen for typing and navigation. The iPad is an example of a tablet.
Servers
showing servers
A server is a computer that serves up information to other computers on a network. For example, whenever you use the Internet, you're looking at something that's stored on a server. Many businesses also use local file servers to store and share files internally.
Other types of computers
Many of today's electronics are basically specialized computers, though we don't always think of them that way. Here are a few common examples.
Smartphones: Many cell phones can do a lot of things computers can do, including browsing the Internet and playing games. They are often called smartphones.
Wearables: Wearable technology is a general term for a group of devices—including fitness trackers and smartwatches—that are designed to be worn throughout the day. These devices are often called wearables for short.
Game consoles: A game console is a specialized type of computer that is used for playing video games on your TV.
TVs: Many TVs now include applications—or apps—that let you access various types of online content. For example, you can stream video from the Internet directly onto your TV.
PCs and Macs
Personal computers come in two main styles: PC and Mac. Both are fully functional, but they have a different look and feel, and many people prefer one or the other.
PCs
showing a pc
This type of computer began with the original IBM PC that was introduced in 1981. Other companies began creating similar computers, which were called IBM PC Compatible (often shortened to PC). Today, this is the most common type of personal computer, and it typically includes the Microsoft Windows operating system.
Macs
showing a mac
The Macintosh computer was introduced in 1984, and it was the first widely sold personal computer with a graphical user interface, or GUI (pronounced gooey). All Macs are made by one company (Apple), and they almost always use the Mac OS X operating system.
Lesson 3: Basic Parts of a Computer
Introduction
The basic parts of a desktop computer are the computer case, monitor, keyboard, mouse, and power cord. Each part plays an important role whenever you use a computer.
Watch the video below to learn about the basic parts of a computer.
Looking for the old version of this video? You can still view it here.
Computer case
showing computer cases
The computer case is the metal and plastic box that contains the main components of the computer, including the motherboard, central processing unit (CPU), and power supply. The front of the case usually has an On/Off button and one or more optical drives.
Computer cases come in different shapes and sizes. A desktop case lies flat on a desk, and the monitor usually sits on top of it. A tower case is tall and sits next to the monitor or on the floor. All-in-one computers come with the internal components built into the monitor, which eliminates the need for a separate case.
Monitor
showing a computer monitor
The monitor works with a video card, located inside the computer case, to display images and text on the screen. Most monitors have control buttons that allow you to change your monitor's display settings, and some monitors also have built-in speakers.
Newer monitors usually have LCD (liquid crystal display) or LED (light-emitting diode) displays. These can be made very thin, and they are often called flat-panel displays. Older monitors use CRT (cathode ray tube) displays. CRT monitors are much larger and heavier, and they take up more desk space.
Keyboard
The keyboard is one of the main ways to communicate with a computer. There are many different types of keyboards, but most are very similar and allow you to accomplish the same basic tasks.
Print Screen, Scroll Lock, Pause/Break
The Print Screen, Scroll Lock, and Pause/Break keys are at the top-right corner of the keyboard. The Print Screen key takes a picture of your screen (called a screenshot) that you can edit or save using a graphics program. Scroll Lock and Pause/Break are rarely used today, so some keyboards don't have them.
keyboard
Escape Key
The Escape (Esc) key allows you to stop a function or action. For example, if a webpage is taking a long time to load, you can press the Escape key to stop loading it.
keyboard
Function Keys
The function keys are labeled F1 through F12. Some programs use these keys as shortcuts for common tasks. For example, in many programs, F1 opens the Help file.
keyboard
Tab Key
The Tab key is used to create indents in word processing programs. Also, if you are filling out a form online, you can use the Tab key to switch to the next field.
keyboard
Alphanumeric Keys
The main part of the keyboard includes the alphanumeric keys (letters and numbers) and the spacebar.
keyboard
Ctrl, Alt, and Shift
The Control (Ctrl), Alternate (Alt), and Shift keys are designed to work in combination with other keys. Typically, you hold down Ctrl, Alt, or Shift and then type another key to perform a specific task. For example, in many programs, typing Ctrl+S will save a file.
keyboard
Arrow Keys
The arrow keys are used for many different purposes, including moving the cursor, scrolling a document, and controlling a game.
keyboard
Numeric Keypad
The numeric keypad resembles a calculator keypad. Many users find that it is easier to type numbers using this keypad. On some keyboards, these keys double as arrow keys.
keyboard
Backspace Key
The Backspace key (also known as the delete key) erases the character to the left of the cursor.
keyboard
Enter
The Enter key (also known as the return key) executes commands. For example, while on the Internet, you can type a website address and then press Enter to go to the site. It is also used to start a new line in word processing programs.
keyboard
Home and End
These move the cursor to the beginning or end of the current line.
keyboard
Insert and Delete
Insert: This switches between insert mode (which inserts new text without deleting anything) and overtype mode (which deletes text after the cursor as you type).
Delete: This erases the character to the right of the cursor.
keyboard
Page Up and Page Down
These scroll a document or webpage up or down.
keyboard
If you want to learn how to type or improve your touch-typing skills, check out our free Typing Tutorial.
Mouse
showing a mouse
The mouse is another important tool for communicating with computers. Commonly known as a pointing device, it lets you point to objects on the screen, click on them, and move them.
There are two main mouse types: optical and mechanical. The optical mouse uses an electronic eye to detect movement and is easier to clean. The mechanical mouse uses a rolling ball to detect movement and requires regular cleaning to work properly.
To learn the basics of using a mouse, check out our interactive Mouse Tutorial.
Mouse alternatives
There are other devices that can do the same thing as a mouse. Many people find them easier to use, and they also require less desk space than a traditional mouse. The most common mouse alternatives are below.
Trackball: A trackball has a ball that can rotate freely. Instead of moving the device like a mouse, you can roll the ball with your thumb to move the pointer.
Touchpad: A touchpad—also called a trackpad—is a touch-sensitive pad that lets you control the pointer by making a drawing motion with your finger. Touchpads are common on laptop computers.
