Hardware

The term “hardware” refers to the physical parts of a computer system. Hardware appears both inside and outside the computer. Peripheral devices are equipment used with a computer to enhance its functionality. They are devices that are “outside” of or in addition to, the computer (i.e. printer, scanner, and modem).The basic hardware of a com­puter system includes:

Case: The box that holds the circuitry for the computer. One of the main chips inside is called the central pro­cessing unit or CPU for short. This acts as the “brain” to send instructions to other parts of the computer. Al­though there are other factors to consider, the higher the speed of the CPU, the faster the computer can send and receive information.

Drives: Nearly all computers have an internal hard drive used to store information. There are many other types of drives, such as external hard drives, CD and DVD drives that can be used to store information on CDs or DVDs.

Keyboard: The device used to type and enter information into the computer.

Mouse: A pointing device used to move the cursor displayed on the monitor. Laptops generally use a track pad or touch pad instead of a mouse to move the cursor.

Monitor: The screen that shows the information for the computer; also called a display. Newer com­puters have LCD (liquid crystal display) monitors that are thinner than the older monitors.

Printer: The printer takes the information displayed on the screen and prints it on paper. The most common types of printers are ink jet (left), which are typically used in homes and small businesses, and laser printers (right), which are used in schools and large businesses.

The Keyboard

The keyboard is the standard device used to enter information into the computer’s memory. It looks and operates much like a standard typewriter keyboard and includes the 26 letters of the alphabet, the 10 digits used for numbers, and some special characters.In addition to these standard keys, the keyboard also has special sets of keys.

On the right-hand side of the keyboard is the numeric keypad. To the left of the numeric keypad are the arrow keys, Home, End, Pg Up, and Pg Down keys, which allow movement around the computer screen. At the top or left-hand side of the keyboard are keys labeled F1, F2, F3,…F12. They are referred to as function keys. These keys perform special functions depending on the program you are working in.Other special keys you will use include:

Shift: The Shift key works like the familiar shift key on a typewriter.

Alt: The Alternate (Alt) key is used in combination with other keys to

send special commands to computer programs.

Ctrl: The Control (Crtl) key works like the Alt key. It is always used in

combination with some other key.

Esc: The Escape (Esc) key is used to escape or leave some function you

have selected. The Escape key is always used by itself.

Enter: The Enter key is typically used to end a paragraph when working in

most application programs or to execute a command.

Tab: The Tab key is typically used to move the insertion point across the

screen to the next tab stop, in the same manner as a tab key on a

typewriter.

Backspace: The Backspace key, located directly above the Enter key, deletes the

character to the left of the insertion point.

Delete: The Delete key, located to the right of the Enter key, deletes the

Character to the right of the insertion point.

All the keys on the keyboard are auto-repeat keys. This means that if you hold the key down, the character or function that the key performs will be repeated as long as the key is held down.

LCD Monitors (Liquid Crystal Display)

Liquid-crystal displays (LCD), in the past restricted to notebooks, are now a reality for desktops. The three greatest advantages of this type of video monitor compared to traditional tube-based monitors (CRT, Cathode Ray Tube) are the use of less space on the desk (especially 17" models or bigger), less power consumption and 100% flicker-free, even with a refresh rate of only 60 frames per second (60 Hz).

The most important thing you need to know about LCD technology is that LCD panels have a fixed resolution. This resolution is called “native resolution,” “maximum resolution” or simply “resolution” and you must configure your desktop to that resolution, otherwise two things can happen, depending on the model of your monitor:

1. The monitor will centralize the image in the new resolution, reducing the image size and inserting a black frame around the image. For instance, if your LCD native resolution is 1280x960 and you decreased it to 800x600, this means there are 480 pixels left horizontally (1280 - 800) and 360 pixels left vertically (960 - 600). The image will be centralized and there will be 240 black pixels above and below the image and 180 blank pixels on the sides of the image.

2. The monitor will try to stretch the image in order to not show the black area around of the image, filling the whole screen. This is done through a technique called interpolation, which isn’t 100% perfect and thus you will feel that the image has better quality (definition) when the screen is configured at its native resolution, even though the elements on the screen (e.g., icons, letters, etc) will be smaller. In general you will feel that the image is slightly out of focus (blurred) when the monitor is not configured in its native resolution.

Because of this inherent characteristic of LCD panels you will have to choose an LCD monitor that has a resolution that you are comfortable with. The higher resolution isn’t always the better. With higher resolutions you have more space on your screen (in other words, more stuff will fit the screen at the same time) but icons and letters will be smaller. So for the average user a monitor with a higher resolution doesn’t always translate into a better product, it will largely depend on the application. If you only use your computer to browse the internet, write e-mails, use spreadsheets and word processing you will probably want to stick with a monitor with a lower resolution, because they are cheaper and won’t make your icons and letters to become very small. But if you run professional applications like video and image editing, then you will probably want a monitor with higher resolution and screen size.

If you are a gamer, you must buy a monitor that matches the resolution you want to play, otherwise the game will look like “blurred.” In other words, configure your game to run at the display’s native (i.e., maximum) resolution. All gamers know that when you increase the game resolution the performance lowers (because there will be more pixels to be drawn on the screen). If your game is running too slow, that means it is time to upgrade your video card. You can decrease the game resolution but, as we are explaining, you will hurt image quality.

Learn About Computer Software

Computer software provides the instructions that enable the computer hardware to perform its tasks. Without software, your monitor would not display anything, your

Speakers would remain silent, and typing on the keyboard keys would have no effect. Computer software comes in two basic categories.

1.Application Software

2. System Software

Application Software

Application software refers to the programs that you interact with to perform specific computer tasks. For example, a word-processing program enables you to create documents such as memos and letters, a graphics program enables you to draw an image, and an e-mail program enables you to send and receive e-mail messages.

System Software

System software refers to programs that operate behind the scenes to ensure that your computer system functions properly. This software is most often referred to as the operating system. Some examples of system software include Windows XP and Mac OS.

Learn About Computer Hardware

Computer hardware consists of the physical components of your computer: the parts, devices, buttons, and ports that you can touch and physically manipulate. Computer hardware comes in two basic varieties.

1.External hardware

2. Internal hardware

External Hardware

External hardware, also known as peripherals, refers to hardware that connects to the outside of the computer case. The monitor, keyboard, and mouse are the most common external hardware devices. The printer and speakers are also popular peripherals. You can connect external hardware to your computer through the computer ports.

Internal Hardware

Internal hardware refers to hardware that resides inside the computer case. This includes the central processing unit (CPU)  the brains of the computer, memory chips that are used for temporary data storage while you work, disk drives that are used for long-term storage, and circuit boards that supply many of the ports on the back of the computer case.

Modem

The modem is a device that connects your computer to the Internet, either through telephone lines or TV cable. Some modems, called internal modems, reside inside the computer case.

Game Controller

The game controller is a device that you can use to control the action in a computer game.

Uninterruptible Power Supply (UPS)

An uninterruptible power supply (UPS) is a device that provides temporary power to your computer should the electricity fail. This device enables you to shut down your computer properly to avoid losing data.

Speakers

The speakers are devices that output the sound effects, music, narration, and other audio that your computer generates. You can also use headphones so that only you can hear the computer's output.

Printer

A printer is a device that you use to print a document from a computer.Some printers are all-in-one devices that can also fax, copy, and scan documents.

Personal Computer Accessories

Besides the keyboard and mouse, most personal computers also come with a number of accessories.

1.Printer

2.Speakers

3.Uninterruptible Power Supply(UPS)

4.Game Controller

5.Modem

The Mouse

The mouse is a hand-operated pointing device that you use to select or move items on the screen, as well as to provide instructions for the computer to follow.

The Keyboard

The keyboard is a typewriter-like device that you use to type information and enter instructions for the computer to follow.