Everyone has ego states, if you look up Eric Bernes his model is very understandable, ie adult, child, parent states.

A singleton has ego states making up the personality. The child part is feelings, needs and wants. The adult part is the reasoning, learning part. The parent part is the rules and customs.

A multiple has many parts. The ego states (child, adult and parent) are split into different groups. ie each child part has it's own set of feelings, with different adult- intelligence level and possibly different parental rules. Every multiples system is different but usually have more child parts than most.

Hope my post is understandable and helps.

You like asking questions. Can I ask you why are you asking so many questions? Do you have DID? Are you a student doing reseach? Why do you need to know?