Русско-англо-русский юридический словарь

A forum is a place where disputes are heard and decided, such as a tribunal or court. (USLegal)

Venue (law) is the location where a case is heard. (Wikipedia)

Although venue and forum selection clauses are closely related, a venue selection clause sets the geographic location for the resolution of any dispute, while a forum selection clause chooses the particular court or arbitrator that will decide the matter. (Beck Reed Riden LLP website)