A computer mouse is a small object that enables a user to control a cursor on a screen. The most common type of computer mouse contains two buttons and varies in shape, but is usually pointed-shaped, with one button conveniently built into the thumb area of the pointer. As pressure from your hand on the mouse moves the ball inside from side to side, this corresponds with movement on-screen as well. There are many different types of computer mice for various purposes – some have adjustable weights so you can choose how heavy your movements are relative to screen action while others have many buttons which allow more things to happen at once when pressed simultaneously or alternately, while others work wirelessly without any wires plugged into them at all!.