Escorted Tour: is a prepaid, structured program of sightseeing, meals, and Accommodations for a group of people traveling together accompanied by an Escort from the beginning to the end of the trip.
Motorcoach tours are an example.
Other definition:
An organized tour led by a professional tour manager.
Other definition:
Escorted Tour is a pre-arranged travel program, usually for a group, with host service. Fully escorted tours also may use local guide services.
The Travel-Glossary: Everything about Travelling, Sightseeing and the World.