When something subsumes something else, it includes or contains it.
Subsumes is a big word that means one thing is a part of another thing.
Examples:
The category of fruit subsumes apples and oranges.
The rule subsumes all cases.
The big group subsumes the small group.
The umbrella subsumes the rain.
The library subsumes all the books in the world.
The family subsumes all the people in the house.