Trial placement (prototype)
Beginner
A quick, rough practice run of placing the parts, to check a floorplan before doing the real thing.
Novice
A quick, rough placement of the whole design into the floorplan, followed by an estimate of wiring crowding and a rough speed check, to see whether the plan can work. It is thrown away afterwards.
Expert
Often run on clusters of cells rather than individual cells, which shrinks the problem. Its congestion map and worst timing paths point back at macro positions, channel widths and pin locations. Its numbers are trends, not final results.