An AudioBuffer is a data structure used in web audio programming to store audio data in memory. It allows developers to manipulate sound by providing a way to hold audio samples, which can be played back, processed, or modified. The AudioBuffer can contain multiple channels, making it suitable for stereo or multi-channel audio applications. In the context of the Web Audio API, an AudioBuffer is created using the AudioContext interface. Once created, it can be filled with audio data from various sources, such as AudioFile or synthesized sounds. This flexibility makes it a crucial component for building interactive audio experiences on the web.