Basic Computers - Lesson 4

What is an operating system?

An operating system is the most important software that runs on a computer. It manages the computer's memory, processes, and all of itssoftware and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's "language." Without an operating system, a computer is useless.

The operating system's job

You've probably heard the phrase boot your computer, but do you know what that means? Booting is the process that occurs when you press the power button to turn your computer on. During this process (which may take a minute or two), the computer does several things:

• It runs tests to make sure everything is working correctly.
• It checks for new hardware.
• It then starts up the operating system.

In the image below, you can see the start-up screen that appears when you turn on a Windows 7 computer.

Once the operating system has started up, it manages all of the software and hardware on the computer. Most of the time, there are many different programs running at the same time, and they all need to access your computer'scentral processing unit (CPU), memory, and storage. The operating system coordinates all of this to make sure each program gets what it needs. Without the operating system, the software wouldn't even be able to talk to the hardware, and the computer would be useless. In the image below, you can see how Windows 7 appears after starting up.

Basic Computers - Lesson 3

PCs and Macs

Personal computers come in two main styles: PC and Mac. Both styles are fully functional, but they do 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 to create 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.

Although PC can refer to an IBM PC Compatible, the term can also be used to refer to any personal computer, including Macs.

About this tutorial

In this tutorial, we'll mostly be focusing on PCs and the Windows operating system. If you're using a Mac, you may notice some differences with the way your computer works. However, much of the information in this tutorial will still apply, no matter which type of computer you're using.

 

Basic Computers Lesson 2

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 laptopcomputer. 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 the cost. If you compare a desktop and a laptop with the same features, you will most likely find that the desktop computer is priced lower.

Some desktop computers have a built-in monitor to save space. These are often called all-in-one desktop computers.

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 aremore 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. However, it's usually possible to add more RAM or a larger hard drive.

A laptop computer is sometimes called a notebook computer because of its size.

Servers

A server is a computer that "serves up" information to other computers on a network. Many businesses have file servers that 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, aweb 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:

• Tablet computers: These use a touch-sensitive screen for typing and navigation. Because they don't require a keyboard or mouse, tablet computers are even more portable than laptops. The iPad is an example of a tablet computer.
• 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.

Basic Computers - Lesson 1

A computer is an electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and browse the Web. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.

Computers simplified

For beginner computer users, the computer aisles at an electronics store can be quite a mystery, not to mention overwhelming. However, computers really aren't that mysterious. All types of computers consist of two basic parts:

• Hardware is any part of your computer that has a physical structure, such as the computer monitor or keyboard.
• 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 such as Microsoft Word.

Anything you buy for your computer can be classified as either hardware or software. Once you learn more about these items, computers are actually very straightforward.

The first electronic computer, the Electronic Numerical Integrator and Computer (ENIAC), was developed in 1946. It took up 1,800 square feet and weighed 30 tons.