Working of trackball

Answer 1

Trackballs are really upside-down, roller-bearing mice. Instead of the ball being inside the body, the ball is on the outside of a trackball and you move just the ball instead of the mouse body. Trackballs have several advantages over mice. Because you don't actually move the trackball itself, it takes up less space than a mouse does. And you don't have to lift it up to move it when you run out of room or reach. Because your hand remains stationary, you don't rub the sensitive areas of your wrist across the edge of your desk, which can lead to damage of the tissues in your forearm. Trackballs also have more than one button, and you can program the other buttons to perform various functions. For example, you can set a button to add a modifier key to the click so that you can bring up contextual menus with a click instead of having to hold down the Control key while you click. And trackballs can move the cursor either faster to cover more screen real estate or more slowly to give you more precise control than a mouse.

Choosing a trackball is similar to choosing a keyboard or mouse (except that Macs don't ship with a "default" trackball). Look for one that fits your hand and has the features you want?such as the number of buttons it has.