How is the mid-ocean ridge different from the mountains of the land?

Mid-ocean ridges (MOR) and land mountains have several differences. Firstly, the oceanic ones are much longer and form an almost continuous chain across all the oceans, although in some places the ridge is still interrupted. Secondly, if land ones are formed at the junctions of two tectonic plates, then oceanic ones are formed at the places where they diverge. Land mountains are of different origins, the underwater ridges are all volcanic. They are younger and more active, forming new crust, and on land the mountains are prone to erosion.