COMPUTER BASIC

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 can use a computer to type documents, send email, and browse the internet. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.


Watch the video to learn about different types of computers


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Computers Simplified

For beginning 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 are web browsers, games, and word processors such as Microsoft Word.

Anything you buy for your computer can be classified as either hardware or 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 computer. 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 usually sit on a desk. Once you add a monitor, mouse, and a 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 alaptop 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 that you may be familiar with is a laptop computer, or laptops as they are often referred to. Laptops are battery or AC-powered personal computers that are more portable than desktop computers, allowing you to use them almost anywhere.

Since a laptop is smaller than a desktop, it's more difficult to access the internal components. That means you may not be able to upgrade them as much as a desktop. However, it's usually possible to add more RAM or a bigger hard drive.

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

Servers

A server room

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

The iPad, a type of tablet computer

• Tablet Computers: These use a touch-sensitive screen for typing and navigation. Since 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 a computer can do, such as browsing the internet or 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 a desktop computer, many newer consoles, such as theNintendo Wii, allow you to do non-gaming tasks like browsing the internet.
• TVs: Many TVs now include applications (or apps) that let you access various types of online content. For example, you can view yourFacebook news feed or watch streaming movies on Netflix.

Challenge!

• Think about the activities you perform or want to perform using a computer (email, online shopping, etc.).
• Think about all the computers that are necessary for you to complete your day-to-day activities.
  • Is it a computer that controls the stoplights so you can drive to work?
  • How did the cashier scan and calculate your grocery items?
  • Does the coffee store you visit use a computer to order their inventory?
  • Is the weather map on television computer-generated?

Basic Parts of a Desktop Computer

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.

Computer Case

The computer case is the metal and plastic box that contains the main components of the computer. It houses the motherboard, central processing unit (CPU), the power supply, and more.

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. The front of the case usually has an on/off switch and one or more optical drives.

Most of the personal computers you can purchase today include tower cases, rather than desktop cases; however, some computers are being made with all of the internal components built into the monitor, which completely eliminates the tower.

Monitor

The monitor works with a video card, located inside the computer case, to display images and text on the screen. 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 bigger and heavier, and they take up more desk space.

Most monitors have control buttons that allow you to change your monitor's display settings, and some monitors also have built-in speakers.

LED displays are actually LCD displays that are backlit with light-emitting diodes. This allows for greater contrast than a traditional LCD display.

Power Cord

The power cord is the link between the power outlet and the power supply unit in the computer casing. If the power cord is not plugged in, the computer will not power on. To protect your computer from voltage spikes, you can plug the power cord into a surge protector. You can also use an Uninterruptable Power Supply (UPS), which acts as a surge protector and also provides temporary power if there is a blackout.

Keyboard

The keyboard is one of the primary ways we communicate with the computer and enter data. There are many different types of computer keyboards such as wired, wireless, ergonomic, multimedia, and more. Although there may be differences in the location of some keys or features, keyboards are very similar and allow you to accomplish basically the same tasks.

Mouse

The mouse is a peripheral that is known as a pointing device. It lets you point to objects on the screen, click on them, and move them.

There are two main types of mice: 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. Generally, a mechanical mouse is cheaper, although it may require regular cleaning to keep it working properly.

Traditionally, a mouse connects to the computer using a USB or PS/2 connection. However, you can also buy a wireless mouse, which can reduce clutter on your desktop.

Mouse Alternatives

There are other devices that can do the same thing a mouse can do, but with a different look and feel. Many people find them to be easier to use, and they also require less desk space than a mouse. The most common mouse alternatives include:

Trackball: A trackball has a ball on top that can rotate freely. Instead of moving the device like a mouse, you can simply roll the ball with your fingers to move the pointer. Some mobile devices have miniature trackballs that can be controlled with your thumb.

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 very common on laptop computers.

Challenge!

Think about the desktop computers you've seen at work, school, the library, a store, or a friend's house. What did they look like? Were they all-in-one, or did they have a separate tower?

Review the Parts of the Keyboard interactive on page 3 of this lesson. Are there any keys that you haven't used before?

If you're using a mouse, flip it over to see whether it's optical or mechanical.

Is your monitor LCD, LED, or CRT?

If your monitor has control buttons, try adjusting the brightness and contrast.

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INTERNET

Introduction

 

It's no secret that more and more the Internet is becoming an integral part of our everyday lives. But if you are new to the online experience, it may be a bit overwhelming. You may be wondering, "What exactly is the Internet, and how does it work?"

In this lesson, we will give a brief overview of the Internet, and we will talk about some fundamental concepts such as networks, servers, and clients.

The Internet Today

In the early days, most people just used the Internet to search for information. Today's Internet is a constantly evolving tool, that not only contains an amazing variety of information, but also provides new ways of accessing, interacting and connecting with people and content.

As a result, new terms are constantly appearing as new technologies are introduced. The interactive below contains a few common terms that you might encounter online.

What is the Internet?

The Internet is the largest computer network in the world, connecting millions of computers. A network is a group of two or more computer systems linked together.

There are two main types of computer networks:

1. Local Area Network (LAN): A LAN is two or more connected computers sharing certain resources in a relatively small geographic location, often in the same building. Examples include home networks and office networks.
   

Wide Area Network (WAN): A WAN typically consists of two or more LANs. The computers are farther apart and are linked by telephone lines, dedicated telephone lines, or radio waves. The Internet is the largest Wide Area Network (WAN) in existence. 

Servers and Clients

A server with multiple clients

You may have heard someone say something like "The server is down" or "We're having problems with the e-mail server." A server is a computer that "serves" many different computers in a network by running specialized software and storing information. For example, web pages are stored on servers.

When you access a web page, your computer is acting as a client. A client runs familiar software such as web browsers or email software, and it communicates with the server to get the information it requires.

In order for your browser to display a web page, it requests the data from the server where the page is stored. The server processes the request, then sends the data to your browser, where it is displayed.

In peer-to-peer (P2P) networks, each computer acts as both a server and a client. Examples of P2P software include Skype and BitTorrent.

Did you know?

• The foundation of the Internet began in 1969, when the US Department of Defense created ARPAnet, a project to allow military personnel to communicate with each other in an emergency.
• By 2011, the number of Internet users worldwide reached 2 billion—over one quarter of the world's population.

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