The best way to understand these terms is to look at common usage in real life. Usage varies from country to country. It is fair to say, however, that common usage originated from England in public life. Here is how these terms are usually used in England. 1. Commission - usually used in "a commission of enquiry" into a controversial issue, a disaster or a public scandal. This is a good reference article: https://en.m.wikipedia.org/wiki/Royal_Commission 2. Council - a council is normally a quasi-government body, e.g. the Arts Council, or the governing body of a public or a not-for-profit entity, e.g. a city council; the council of a school. 3. Committee - any group of people formed to perform a task can be a committee, e.g. the committee for the annual school bazaaar; the fund-raising committee of a charity; the standing committee of the People's Congress. "Committee" is more frequently used than the other two terms because of its wide applicability.