Yes, that is the reason oceanic crust is at a lower elevation compared to continental crust. Oceanic crust sub-ducts under the less dense continental crust. Continental crust is much older than oceanic crust, because oceanic crust is constantly being destroyed and created.
There are two types of crust, and they are the oceanic crust and the continental crust. Oceanic crust is thinner yet more dense than continental crust, and continental crust is on average older than oceanic crust :)