Here's a breakdown:

* Thickness: Oceanic crust is typically 5-10 kilometers thick, whereas continental crust is 30-70 kilometers thick.

* Density: Oceanic crust is denser due to its composition, primarily basalt and gabbro. Continental crust is less dense, mainly composed of granite and andesite. This density difference is why oceanic crust sits lower than continental crust.

* Age: Oceanic crust is constantly being created at mid-ocean ridges and subducted back into the mantle at subduction zones. This constant cycle means that the oldest oceanic crust is only about 200 million years old, while continental crust can be billions of years old.

Let me know if you'd like to know more about the differences!