MOUSE

Until the invention of software using GUI's, the keyboard was the only way that most people input information into their PCs. Mice are used in graphical environments to let users provide simple "point and click" instructions to the computer. The main advantage of a mouse over the keyboard is simplicity. There are also some operations that are much easier to perform with a mouse than a keyboard (such as picking an item on a screen or choosing from a list of options). Generally, if the mouse has two buttons, the left one is used to select objects and text and the right one is used to access menus. If the mouse has one button (such as with Mac PC's), it controls all the activity. A mouse with a third button can be used by specific software programs. Track balls and touch-pads are variations on the mouse that are used with laptops.