MP3 is a digital audio coding format that was developed in the late 1980s and early 1990s. It is a form of lossy compression that is used to reduce the size of audio files while maintaining acceptable sound quality.

The MP3 format works by compressing audio data so that it takes up less space on a computer or mobile device. This is accomplished by removing data that is deemed unnecessary or less important to the overall sound quality of the recording. This process is known as "lossy" compression because it results in some loss of audio data, which can lead to a reduction in sound quality.

Despite this loss of data, the MP3 format has become extremely popular and is now one of the most widely used audio formats in the world. This is due to the fact that it allows users to store and transmit large amounts of audio data in a relatively small amount of space.

MP3 files can be played back on a wide range of devices, including computers, smartphones, and portable music players. They can also be streamed over the internet, making them a popular choice for online music services such as Spotify and Apple Music.

In recent years, the popularity of the MP3 format has declined somewhat, as newer, more advanced audio formats have been developed that offer better sound quality and more efficient compression. However, the MP3 format remains a popular choice for many users due to its widespread compatibility and ease of use.