EasyTag is a graphical utility to edit the descriptive ID3 tags for your music files. One will think primarily of MP3 files, but it also does other formats, such as Ogg, FLAC, MP4/AAC, MusePack, Monkey’s Audio files and WavPack files (APE tag).
When you listen to digital music, your software or hardware player usually shows information about the current song, which it gets from MP3 tags or Ogg Vorbis comments. Most ripping software supports acquiring this metadata from the CDDB or FreeDB services based on a CD's disc ID. But you can also can fill in and edit metadata with tools such as EasyTag and Picard.