A computer mouse enables its user to move a cursor smoothly and intuitively across a two-dimensional plane. It's therefore an essential input device for selecting, dragging, hovering, and clicking. The mouse allows users to switch between applications, select options and buttons, and move around the screen with a great degree of accuracy and fluidity. It is used to move between and select links on a website, buttons on an options screen, entries on a menu, and many more tasks that would be far more difficult using a keyboard alone.