What is a "package tour"?

The meaning of a small tour group is simply that several good friends want to go out to play by themselves, but they don't want to join the group with strangers, so they organize themselves into small teams, and the expenses are calculated independently according to the number of people. One advantage of a small tour group is that the members of the group are close relatives or friends. Suitable for small tour groups are generally small groups organized by themselves, such as good friends, colleagues, relatives and friends. I wonder if this explanation is detailed enough? If it is not detailed enough, you can look for it in travel books.