Cordless mouse and keyboard for a computer. The mouse is also optical and has a scroll wheel. It is called an optical mouse because LED (light- emitting diode) sensors inside the mouse track the motion of the mouse as it is moved across a surface. Data from the mouse is transmitted to the computer. Standard mice use an electrical cord to transmit this data, but several designs of cordless mice are available. Most use either infrared or radio waves to send the signal to the computer. The end result is a matching movement for a pointer on the computer screen. The pointer is used to interact with the computer. A keyboard transmits text-based commands and data.