Tour Guide

A tour guide provides assistance, information and cultural, historical and contemporary heritage interpretation to people on organized tours and individual clients at educational establishments, religious and historical sites, museums, and at venues of other significant interest.

The CEN (European Committee for Standardization) definition for "tourist guide" – part of the work by CEN on definitions for terminology within the tourism industry – is:
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 recognized by the appropriate authority.

[Wikipedia]