What is a tour group? Please give a clear explanation as to whether there is a limit to the number of people in a "group" and how many people count as a group.

Small groups organized by travel agencies for the purpose of tourism are called tour groups.

There is no limit to the number of tour groups. I once joined a tour group with only two tourists. At that time, our group was 1 tour guide, 1 driver and 2 tourists.

For long-distance travel, in order to ensure profits, general travel agencies have a group size limit. If there are fewer people, there will be no group.

Supplementary answer:

Generally speaking, there is no limit to the number of people. The main reason is that travel agencies feel that there is no guarantee of profit without people, so there will be a limit on the number of people.

If the landlord himself is willing to contribute, a one-person tour group is also possible. Whether it is an outbound tour or a domestic tour, it is the same.