To clarify what I'm going on aboot, I use the terms in this way;
I use the term "docking lines" for lines that I use in the process of docking as well as while temporarily attaching myself to a dock. I mean, they are not permanently fixed to the dock.
I use the term "mooring lines" for lines that are permanently attached to where I moor. Although we often think of this as a mooring ball, it is not limited to such. No translation required, "mooring" has the same meaning in the simplified, American English version of the dictionary. (g). In my case, the mooring will be floating docks at the club
A typical practice, and often requirement, at yacht clubs is to permanently attach chain to the docks (or cleats) and then the lines are permanently attached to the chain via a thimble spliced into the mooring line. This provides a strong attachment point with good chafe protection... good for safety, good for club insurance. :-)
I boil it down to mooring lines stay on the dock, docking lines are kept aboard the boat.