convmv is meant to help convert a single filename, a directory tree and the contained files or a whole filesystem into a different encoding. It just converts the filenames, not the content of the files. A special feature of convmv is that it also takes care of symlinks, also converts the symlink target pointer in case the symlink target is being converted, too.
These details are provided for information only. No information here is legal advice and should not be used as such.