The answer is audio files and compressed files.
The .mp3 file is typically associated with MPEG audio stream and is a coding format for digital audio files. MP3 file types often designates files that contain MPEG-1 audio and video encoded data .
A .zip file is a compressed file usually in ZIP format that is widely used to archive a computer supported file format. Files associated with .zip extensions are compressed into a single file for easy transportation.