Politics
One of the ways the government leads the group is by making laws and rules which tell everybody what they can and can not do. The government makes these laws so that society will be safe and well-ordered. The law that says "you must not drive a car when you have been drinking alcohol" stops people from drunk driving, which could kill people. The law that says "you must wear a helmet on a motorcycle" makes sure that people protect themselves when riding their motorcycles.