This is very difficult to sort out in a forum like this, simply because there are so many variations to everything, and some people have slightly different wordings for the same thing as others have.
Just think about it:
The camera can autofocus in normal view (live view off) in three different modes (One shot, AI focus and servo AF) with five different selection methods for AF point (spot, single, single expanded, zone auto and full auto).
In live view mode, it can autofocus with all the modes above, plus also the sensorbased live AF, with a different moveable AF frame and in face detect AF, where the user has to move around the priority frame, if there are several faces to choose from.
I manual focus mode, through the viewfinder, the user turns the ring and either looks at the focusing screen, or relies on when the camera tells him focus is OK, in which case we involve all the focus modes above again.
Or the user selects live view and focuses manually whilst looking at the screen, which then could be magnified five or ten times, or not at all.
No wonder it's difficult to comprehend exactly what somebody else is doing, when not seeing it.
I dare say that if you want at quick inspection of the camera's focusing capability, you do like this:
- Set to One Shot AF and set the lens to AF.
- Select single AF point and then select the center one.
- In the live view menu, select Quick mode AF.
- Aim the camera's center AF point at something that has good contrast and is lit by reasonably strong daylight.
- Enter live view.
- Press AF-ON or trigger half-way down (or whatever you have your 7D configured to do the AF procedure with). Wait for the live view image to return before you release the button.
- Press zoom in twice to magnify the live view image ten times.
- Now carefully nudge the focusing ring left-right to see if there's any other setting that makes things better than what the camera did.
If you want to try it again, de-focus the lens manually first, or the AF will simply measure, find it OK and do nothing.
To be simple to do, this reguires an USM lens with full manual focus adjustment.