MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular audio encoding format. It uses a lossy compression algorithm that is designed to greatly reduce the amount of data required to represent the audio recording, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners.
MP3 is an audio-specific format. The compression takes off certain sounds that cannot be heard by the listener, i.e. outside the normal human hearing range. It provides a representation of pulse-code modulation–encoded audio in much less space than straightforward methods, by using psychoacoustic models to discard components less audible to human hearing, and recording the remaining information in an efficient manner. Similar principles are used by JPEG, an image compression format.