In psychology and mental health, the host is the most prominent personality, state, or identity in someone who has dissociative identity disorder (DID)[1] (formerly known as multiple personality disorder).[1] The other personalities, besides the host, are known as alter personalities, or just "alters".[2] Literature sometimes refers to the collection of all of the different personalities as the host, but it is more commonly referred to as the system.[3] The host may or may not be the original personality, which is the personality a person is born with.[1][2] Additionally, the host may or may not be the personality that coincides with the official legal name of the person.[2] Often this is thought to be the root of the person's psyche, or at least a key figure for completion of therapy, whether or not it has integration of the host and alters as a goal.