An MP3 player is a portable audio device people can use to listen to songs saved in the MP3 format. They can use USB cords to connect the device to computers, so that files can be transferred. MP3s are audio files that have been made smaller by removing sounds that the human ear cannot hear. Many newer MP3 players can also be used to view images or movies, or play games. The most well-known MP3 player is the iPod.