Group tours are pre-arranged tours with fixed dates. The advantage of this kind of tours is that the group is formed from individual tourists who pay a lower price by traveling in a joint group of the same individuals than if they ordered an individual tour which would turn out to be much expensive. The main advantage in saving the money in group tours is that, cost for transportation, cost of guides and special group rates in the hotels are divided proportionally among all the participants of group tours.
Also, these kinds of tours are great to those who want to meet new people. However, participation in such a tour requires a certain discipline and mutual respect for the interests of other members of the group.