Is it earth. crust  , mantel  , outer core , inner core.

crust - rough edges. mantel - constantly moving fluid. inner and outer core - same use .

Is it

the Earth?

The four layers are:

the crust, the mantel, the outer core and the inner core.
The crust has rough edges.
The mantel is constantly moving fluid.
And the inner and outer core have the same use.