§1. A vow is public if a legitimate superior accepts it in the name of the Church; otherwise, it is private.
§2. A vow is solemn if the Church has recognized it as such; otherwise, it is simple.
§3. A vow is personal if the person making the vow promises an action; real if the person making the vow promises some thing; mixed if it shares the nature of a personal and a real vow.
Source: Code of Canon Law (Vatican.va)