In the clans, (Excluding BloodClan, kittypets, rogues, and others) the roles of all of the cats are important. Here are the roles of cats in the clans:
Medicine Cats
In each clan, there should be at least one medicine cat. The medicine cat's roles are to be the healer of the clan for any sickness or injury found within and sometimes outside of the clan. They are also one of two cats in the clan that receive dreams from StarClan. The other is the leader. They can only share their dreams with the leader. They also have a Medicine Code. It will be explained later. Medicine cats can also take apprentices to later become future medicine cats, which doesn't mean that the medicine cat has to pass away or retire.
Leaders
In each clan, there is a leader. The leader leads the clan and watches over it, keeping the clan safe and protected. A leader can send out patrols to check the border between clans, a hunting patrol for bringing back fresh-kill (freshly killed prey) , or a patrol to check whether something is wrong or not. The role of a leader is a very important responsibility to uphold. They receive messages from StarClan along with medicine cats, and they must only tell the medicine cat cat of the clan about their dreams.
Deputies
In each clan, there is a deputy. The deputy's role is basically like a mini version of the leader's role. A deputy is picked by a leader. Deputies can only be deputies if they have mentored at least one apprentice. They also relay updates to the leader.
Warriors
In each clan, there is a most likely chance that there are warriors in them. A warriors duty is to follow instructions from the leader or deputy. If assigned by the leader, they can have apprentices, and cannot have another until their apprentice is a warrior.
Medicine Apprentices
In each clan, there can be a medicine apprentice. As I mentioned earlier, medicine cats can take medicine apprentices to become future medicine cats. The medicine apprentice's job is to learn about all of the herbs and treatments there are, and to understand and follow the Medicine Code. If the medicine cat dies, retires, or just think that the medicine apprentice is ready to be a medicine cat, the medicine apprentice will visit the Moonstone or Moonpool (In more recent books, it will be the Moonpool) to be approved by StarClan to be a medicine cat. Then, the leader will call a meeting and give the medicine apprentice their medicine cat name.
Elders
Elders are the ones in the clan who share their wisdom and stories with other cats in the clans. They are respected, as they were the previous warriors that served the clan.
Apprentices
In each clan, there can be apprentices, who are training to be warriors. They must be at least 6 moons (months) old to become one. They actually have jobs such as cleaning the elders of ticks and replacing bedding moss. They are trained by an assigned mentor by the leader. When they are about 12 moons old, they are turned into a warrior and is given their warrior name.
Queens
In each clan, there might also be queens. Queens are female cats who are nursing kits or are pregnant with kits. They stay in the nursery until they are fit to go back to their warrior duties.
Kits
In each clan, there can be kits. The kits don't really have a role, but they are important, as they will become future warriors or medicine cats.