This program is designed to rename files. So it will only touch the files' names, it will not modify their contents.
It was made for renaming, but in the Options you can ask it to copy the files instead of renaming them.
It can store a predefined list of actions to reuse them later.
It supports unicode, which means that you can rename files that have characters in Greek, Japanese, Chinese, Arab or any other language. Since most of the programs have problems with such names, it can be useful to be able to rename them to Latin (basic ASCII) characters for example.
As I said, it won't modify the contents of the files.
It will not either modify files' date & time.
It will not modify the ID3 (tag) contained in MP3s; it only read this info for building a new file name.
It does not read any info from files other than MP3s, and even for MP3s it only reads the v1 of the ID3, not the v2.
It cannot be fully controlled from command line, though it supports some parameters.
Note that the contents of this list is not fixed. Except modifying the contents of the files, all the "does not" things may appear in future versions.