Scoreboard
Beginner
The part of a test that keeps score. It compares what the chip did with what it should have done.
Novice
The part of a testbench that collects what the design actually produced and what the reference model predicted, pairs them up, and reports any mismatch.
Expert
Has to cope with outputs that arrive reordered, dropped or duplicated, and must check at the end of a test that nothing is still waiting. A scoreboard that compared nothing passes silently, so tests should also check that it saw traffic.