Vampire society is not a lawless group of bloodsuckers. While there are those who believe that the vampires have the right to rise and take over the world of the kine, there's a group called the Camarilla that believe the Kindred must remained hidden from human eyes. Outnumbered by 100,000 to 1, the Camarilla believe they'll be hunted down and destroyed if humans learn about them. To prevent this from happening, the Camarilla created a tradition known as the Masquerade.
Within the Camarilla there are clans: groups of vampires related to each other through the Embrace with unique Disciplines. There are seven clans, each with their own customs and traditions, each with their own ruler though all clans are ultimately ruled over by the Camarilla.