A modem is a computer device used to connect to the internet, typically through a phone line. It is five letters long and is an acronym for modulator-demodulator. A MOUSE is another computer device used to control the cursor on a computer screen. It is five letters long and is a pointing device that detects two-dimensional motion relative to its surface. A printer is a computer device used to produce a hard copy of documents stored in electronic form. It is seven letters long and is an output device that prints text and graphics onto paper. Lastly, a trackball is a computer device used to control the cursor on a computer screen. It is nine letters long and is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes.