Hello Paws. FC are basically FF14's equivallents of guilds,communities.Some FC focus on Roleplay,pvp,hardcore raid but most do pve content as story or daily roulettes. There are small,medium and large FC dependant numbers of members.Usually medium sized best as possible get to know everyone and yet be fairly active were large way too many people and usually form cliques and small may be no be much active.FC offer FC buff to members such as battle/craft/gather bonus exp and some other dependant which bonus FC prefer but those most used in general. If FC have an house members also have their own place to relax,hang,chill,craft.