Chunk

Audio
Chunks organize and identify data within files as part of the RIFF and WAVE file standards, such as the data (sound) chunk, the format (sometimes called header) chunk, and textual metadata chunks. }}

General
Chunk is

"a subportion of a file used for a specific function. chunks organize and identify data within files as part of the RIFF and WAVE file standards, such as the data (sound) chunk, the format (sometimes called header) chunk, and textual metadata chunks. See also BEXT and INFO chunk."