Plain English Meaning
The official manual for a specific aircraft. It tells the pilot how to operate that exact airplane safely, what its limits are, and what to do when something goes wrong.
Full Definition
The POH/FM is the official document, produced by the aircraft manufacturer and approved by the FAA, that contains the operating limitations, procedures, performance data, and systems descriptions for a specific aircraft. The Pilot's Operating Handbook (POH) is the manufacturer's version, while the Airplane Flight Manual (AFM, often shown as FM) is the FAA-approved version that must be carried in the aircraft. For most modern light aircraft, the two are combined into a single document covering normal procedures, emergency procedures, , , and equipment lists.