* Formation: Oceanic crust is constantly being formed at mid-ocean ridges through a process called seafloor spreading. As new magma rises and cools, it forms new crust, pushing older crust away from the ridge. This continuous process results in a relatively young oceanic crust.

* Subduction: Oceanic crust is denser than continental crust. As the plates move, oceanic crust is subducted (pulled) under continental crust at subduction zones. This process destroys old oceanic crust, limiting its age.

* Age Limits: The oldest oceanic crust is found far from the mid-ocean ridges and is estimated to be around 200 million years old. In contrast, the oldest continental crust can be over 4 billion years old.

In summary:

* Oceanic crust: Relatively young, constantly being created and destroyed.

* Continental crust: Much older, more stable and less likely to be destroyed.