Input and Output devices of computer system

INPUT AND OUTPUT DEVICES

INPUT  DEVICES:-
Mouse:-

While most people don't want to see a mouse running around in their home, they typically don't have a problem seeing one sitting by their computer. This is because, along with the keyboard, the mouse is one of the primary input devices used with today's computers. The name comes from the small shape of the mouse, which you can move quickly back and forth on the mouse pad, and the cord, which represents the mouse's tail. Of course, if you are using a wireless mouse, the analogy does not work so well.

All mice have at least one button, though most mice have two or three. Some also have additional buttons on the sides, which can be assigned to different commands. Most mice also have a scroll-wheel, which lets you scroll up and down documents and Web pages by just rolling the wheel with your index finger.


Early mice tracked movement using a ball in the bottom of the mouse. This "mouse ball" pushed against different rollers as it moved, measuring the mouse's speed and direction. However, now most mice use optical technology, which uses a beam of light to track the mouse's motion. Optical mice are more accurate than roller-based mice and they have the added bonus of not getting dirty inside.

Keyboard:-

As the name implies, a keyboard is basically a board of keys. Along with the mouse, the keyboard is one of the primary input devices used with a computer. The keyboard's design comes from the original typewriter keyboards, which arranged letters and numbers in a way that prevented the type-bars from getting jammed when typing quickly. This keyboard layout is known as the QWERTY design, which gets its name from the first six letters across in the upper-left-hand corner of the keyboard.

While the design of computer keyboards may have come from typewriters, today's keyboards have many other keys as well. Modifier keys, such as Control, Alt/Option, and Command (Mac) or the Windows key (Windows) can be used in conjunction with other keys as "shortcuts" to perform certain operations. For example, pressing Command-S (Mac), or Control-S (Windows) typically saves a document or project you are working on. Most of today's computer keyboards also have a row of function keys (F1 through F16) along the top of the keyboard, arrow keys arranged in an upside-down T, and a numeric keypad on the right-hand side. Some keyboards have even more buttons, allowing you to change the system volume, eject a CD, or open programs such as your e-mail or Web browser.

CD-ROM:-

It Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannot altered or erased. Because of this feature and their large capacity, CD-ROMs are a great media format for retail software. The first CD-ROMs could hold about 600 MB of data, but now they can hold up to 700 MB. CD-ROMs share the same technology as audio CDs, but they are formatted differently, allowing them to store many types of data.

OUTPUT DEVICES

Monitor:-

The term "monitor" is often used synonymously with "computer screen" or "display." The monitor displays the computer's user interface and open programs, allowing the user to interact with the computer, typically using the keyboard and mouse.


Older computer monitors were built using cathode ray tubes (CRTs), which made them rather heavy and caused them to take up a lot of desk space. Most modern monitors are built using LCD technology and are commonly referred to as flat screen displays. These thin monitors take up much less space than the older CRT displays. This means people with LCD monitors have more desk space to clutter up with stacks of papers, pens, and other objects.

"Monitor" can also be used as a verb. A network administrator may monitor network traffic, which means he watches the traffic to make sure the bandwidth usage is within a certain limit and checks to see what external sources may be attempting to access the network. Software programs may monitor the system's CPU performance as well as RAM and hard disk usage.


Finally, monitors also refer to speakers used for monitoring sound. Audio engineers typically use "studio monitors" to listen to recordings. These high-end speakers allow the engineers to accurately mix and master audio tracks. So a sound mixer could be monitoring a recording visually using a computer monitor, while monitoring the sound using audio monitors at the same. As you can tell, "monitor" serves as a rather multipurpose word.
Printer


A printer is an output device that prints paper documents. This includes text documents, images, or a combination of both. The two most common types of printers are inkjet and laser printers. Inkjet printers are commonly used by consumers, while laser printers are a typical choice for businesses. Dot matrix printers, which have become increasingly rare, are still used for basic text printing.


The printed output produced by a printer is often called a hard copy, which is the physical version of an electronic document. While some printers can only print black and white hard copies, most printers today can produce color prints. In fact, many home printers can now produce high-quality photo prints that rival professionally developed photos. This is because modern printers have a high DPI (dots per inch) setting, which allows documents to printed with a very fine resolution.



In order to print a document, the electronic data must be sent from the computer to the printer. Many software programs, such as word processors and image editing programs, include a "Print..." option in the File menu. When you select "Print," you will typically presented with a Print dialog box. This box allows you to select the print output settings before sending the document to the printer. After choosing the appropriate settings, you can hit the Print button, which will send the document to the printer.


Of course for the document to print, the printer must be turned on and connected to the computer. Most modern printers are connected using a standard USB cable. However, some printers can be wirelessly connected to one or more computers over a Wi-Fi network. You can also use more than one printer on a single computer, as long as the correct drivers are installed.


While printers are notorious for breaking down at inopportune times, modern printers are fortunately more reliable than the printers of the past. Of course, keeping extra ink or toner cartridges on hand is still your responsibility.