"Cylinder 4 misfire detected" records firings in cylinder 4 that did not produce the power they should have. The cylinder number is the engine computer's own, and the code stands apart from P0300 in exactly one way: the count was attributed to this cylinder rather than spread across several.
This is a standard code. It means the same thing on every make of vehicle.
The Misfire cyl 4 card is its live counter on the Dashboard, and the Full scan lists cylinder 4's count for the last ten drives and this drive with its share of the total. A recorded drive also carries a misfire rate over that recording, which the Analysis screen and the printed report both use.
The Dashboard's Misfire count cards show one counter per cylinder once the engine is running, next to the Engine speed and Ignition timing traces. The Full scan's On-board self-tests give each cylinder's misfire count for the last ten drives and this drive with its share of the total, and a recorded drive works out a misfire rate over that recording for the Analysis screen and the printed report. The Inspection screen shows whether the Misfire detection monitor is done or still running.