You can describe someone or something as self-contained when they are complete and separate and do not need help or resources from outside.
He seems completely self-contained and he doesn't miss you when you're not there.
他似乎已经完全独立,你不在的时候他并不想念你。
Self-contained accommodation such as a flat has all its own facilities, so that a person living there does not have to share rooms such as a kitchen or bathroom with other people.
Her family lives in a self-contained three-bedroom suite in the back of the main house.
她一家人住在主宅后面一个独立的三居室套房里。