How to distinguish between tourist guide, tour manager + tour escort?

Tourist Guide

Person who guides visitors in the language of their choice and interprets the cultural and natural heritage of an area, which person normally possesses an area-specific qualification usually issued and/or recognised by the appropriate authority

Tour Manager

Person who manages and supervises the itinerary on behalf of the tour operator, ensuring the program is carried out as described in the tour operator’s literature and sold to the traveller/consumer and who gives local practical information.

Tour Escort

Representative of a tour operator providing basic assistance to travellers.

Definitions of tourist guide – tour manager – tour escort