MPEG stands for Motion Picture Experts group, which is an organization that sets the standards for audio and video compression. The 1 refers to the first compression standard and 3 refers to the third codec of the MPEG-1 standard.
Karlheinz Brandenburg worked at the Fraunhofer Institut with Bernhard Grill, Thomas Sporer, Bernd Kurten and Ernst Eberlein to create the MP3 format. They patented it in 1989. The first publicly available MP3 player was MPMan, released in 1998 by Saehan.
MP3 players can store hundreds of songs because of the size of MP3 files. A typical song on a CD ranges from 30 to 60 MB. By converting the song to a MP3 file, the size decreases to about 3 MB.
Codecs are specific algorithms designed to compress music by eliminating imperceptible sounds. This reduces the file size, without compromising sound quality.
The most common way to add music files to a MP3 player is through a USB connection with a computer. Files can also be transferred wirelessly using Bluetooth, infrared ports and Wi-Fi.