Garage floor tiles have two sides, a male side and a female side. Most customers get them reversed.
The male side is the flat side, and the female side is the side with the loops sticking out. There is a peg on the male side that fits into the loop on the female size.
Corners are not used for most wall-to-wall applications. If you are doing a parking pad the corner edge is installed on the right side of the section you are working on.