What is the difference between Hardness and Harden-ability of steel?

There are some differences between hardness and hardenability. Hardness is the surface property of material to give resistance to the penetration or plastic deformation and it is measured by one of the tests......Rockwell hardness test,Brinell hardness test and Vicker hardness test.
On the other hand,hardenability is defined as the ability how the material would be hardened and it is measured by Jominy hardenability test.