A tour driver (driver-guide) and a tour guide are not the same. It is to your advantage when booking a private tour to be sure that you understand the difference and know in advance what you are paying for. A tour guide has a license, usually issued by the state / country. He or she has attended school to learn all about the sites you will see. A guide is permitted to go into the historical sites with you and tell you about the history. Naturally, their services are an additional cost. A tour driver is not licensed, has not attended "guide" school, and is not permitted inside a site to tell you about its history. Naturally, their services will be more economical. Many drivers are just as well versed in the area history as a formal guide. The difference of course is that they have to tell you the facts inside of the vehicle and once you are dropped off, he or she cannot explain anything to you about history as he or she can easily get a fine from the public police.