First, let's get something out of the way...I'm no artist! ??
Now that we've established that, here goes
You're going to get a few different opinions of terminology on some of these structures. And to start, to me, structure is the natural contour of the bottom. Cover is an object on that structure.
Structure: Ridge, ledge, hump, ditch
Cover: Tree, brush, rocks on ridge
I drew a side view of what I call a ridge. I consider a ridge a structure as drawn; sharp top, coming up off the bottom, and running however long.
I was on a roll, so I thought I'd throw in some ledges as well. Basically, steep "steps" on a sloping bank or point.
And finally, a hump. I wanted to point out the difference, again imo, between a hump and a ridge. To me, the ridge has a sharp top; whereas a hump flattens off on top, usually more round in shape, usually a little larger area on top as well; almost like a plateau.
That all said, I think it's great that you're trying to get a grasp on underwater features. I think this is quite possibly the most important, most underlooked thing we can do. I really like to try to visualize the structure/cover I'm fishing, and picture my bait coming across/over/down it. You can impart more lifelike action to your bait doing this.
Of course, good electronics will help in this. When I'm done fishing a spot I have found, I like to side image it from all angles to really get a good mental picture of how it lays out, the cover on it etc...
It's a whole other world down there. I'd love to be able to empty some of my favorite lakes and take a wheeler around the bottom.