WTF are Brawl character files?

[ghost]

Saw this on the WGPU site's showcase. Looked interesting, but I don't know WTF Brawl characters or Brawl character files are. More info, pls?

[rukai]

yknow, like, https://en.wikipedia.org/wiki/Super_Smash_Bros._Brawl

[hoijui]

Exact same scenario here... still not sure after this explanation though. it are files fr exactly this game? levels?

maybe should be explained in the first line of the README.