Keyboard and Mouse

Keyboard is the main input device of a computer. Without a keyboard it is impossible to imagine working on a computer. Keyboard is a lot similar to a typewriter but has added keys that enhance the features and capabilities of a user working on a computer.

keyboard - computer hardwares
The today's keyboards consist of about 101 to 106 keys. The layouts are basically the same with the odd key situated differently. It is generally connected to the PS2 or the USB ports of the motherboard. There are many types of keyboards available these days, but one should always buy that is suitable and comfortable. Some are springy others have mushy feeling.

Yes, you get a keyboard when you buy a computer, but, it is not necessary that you have to use it. Keyboards are an inexpensive item that can be replaced easily. But, it doesn't mean that all keyboards are inexpensive as today's markets have very hi-tech keyboards.

Once you've found a keyboard that you find it comfortable, one of your main concerns should be proper typing form. Repetitive stress injuries are a concern and poor posture can also result in back and neck pain. Sit up straight and find yourself a chair that supports the natural curve in your back. It should be adjusted to your keyboard so that you don't have to lean forward or hunch to type.

Your shoulders should be relaxed with your forearms and wrists fairly level, fingers slightly curved. Wrist pads are made for you to rest your wrists on while taking short breaks, your wrists shouldn't be on them while you type. Don't sit and type constantly, try to take a few breaks every now and then and have a stretch.

Mouse
A device that controls the movement of the cursor or pointer on a display screen. A mouse is a small object you can roll along a hard, flat surface. Its name is derived from its shape, which looks a bit like a mouse, its connecting wire that one can imagine to be the mouse's tail, and the fact that one must make it scurry along a surface. As you move the mouse, the pointer on the display screen moves in the same direction. Mice contain at least one button and sometimes as many as three, which have different functions depending on what program is running. Some newer mice also include a scroll wheel for scrolling through long documents.

Invented by Douglas Engelbart of Stanford Research Center in 1963, and pioneered by Xerox in the 1970s, the mouse is one of the great breakthroughs in computer ergonomics because it frees the user to a large extent from using the keyboard. In particular, the mouse is important for graphical user interfaces because you can simply point to options and objects and click a mouse button. Such applications are often called point-and-click programs. The mouse is also useful for graphics programs that allow you to draw pictures by using the mouse like a pen, pencil, or paintbrush.

There are three basic types of mice:

1. mechanical: Has a rubber or metal ball on its underside that can roll in all directions. Mechanical sensors within the mouse detect the direction the ball is rolling and move the screen pointer accordingly.
2. optomechanical: Same as a mechanical mouse, but uses optical sensors to detect motion of the ball.
3. optical: Uses a laser to detect the mouse's movement. You must move the mouse along a special mat with a grid so that the optical mechanism has a frame of reference. Optical mice have no mechanical moving parts. They respond more quickly and precisely than mechanical and optomechanical mice, but they are also more expensive.