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 probably 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 videos.

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.

• Software is any set of instructions that tells the hardware what to do. It is what guides the hardware and tells it how to accomplish each task. Some examples of software include web browsers, games, and word processors. Below, you can see an image of Microsoft PowerPoint, which is used to create presentations.

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.

Desktop computers

Many people use desktop computers at work, home, school, or the library. They can be small, medium, or large in style, and they usually sit on a desk. Once you add a monitor, mouse, and keyboard, you have what is typically known as a desktop computer.

Most desktop computers are easy to upgrade and expand or add new parts. Another benefit of desktop computers is their cost. If you compare a desktop and laptop with the same features, you will most likely find that the desktop is less expensive.

Laptop computers

The second type of computer you may be familiar with is a laptop computer, or a laptop. Laptops are battery- or AC-powered personal computers that are more portable than desktop computers, allowing you to use them almost anywhere.

Because a laptop is smaller than a desktop, it's more difficult to access its internal components. This means you may not be able to upgrade them as easily as a desktop.

Tablet computers

Tablet computers—or tablets—are handheld computers that are even more portable than laptops. Instead of a keyboard or touchpad, tablets use a touch-sensitive screen for typing and navigation. The iPad is an example of a tablet.

Tablets can't necessarily do anything a laptop or a desktop can do, so you may still want a desktop or laptop to run programs or create documents. But if you just want to be able to play games, check email and social media, or stream music and videos, a tablet may be a good computer replacement.

Servers

A server is a computer that serves up information to other computers on a network. Many businesses have file servers employees can use to store and share files. A server can look like a regular desktop computer, or it can be much larger.

Servers also play an important role in making the Internet work: They are where webpages are stored. When you use your browser to click a link, a web server delivers the page you requested.

Other types of computers

Today, there are many everyday devices that are basically specialized computers, even though we don't always think of them as computers. Here are a few common examples:

• Mobile phones: Many mobile phones can do a lot of things computers can do, such as browsing the Internet and playing games. These phones are often called smartphones.
• Game consoles: A game console is a specialized kind of computer that is used for playing video games. Although they are not as fully featured as desktop computers, many newer consoles, such as the Nintendo Wii, allow you to perform nongaming tasks like browsing the Web.
• TVs: Many TVs now include applications—or apps—that let you access various types of online content. For example, you can view your Facebook News Feed or watch streaming movies on Netflix.

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.

• 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.
• 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 Inc., and they almost always use the Mac OS X operating system.