Final answer:
The absolute ceiling is the highest altitude an aircraft can fly without losing stability or control. A single-engine ceiling is the maximum altitude a single-engine aircraft can reach and maintain in level flight.
Step-by-step explanation:
The absolute ceiling of an aircraft refers to the maximum altitude that it can reach under standard atmospheric conditions, regardless of its performance or weight. It is the highest altitude an aircraft can fly without losing stability or control. This limit is determined by factors such as the thrust of the engines, aerodynamics, and air density.
A single-engine ceiling is the maximum altitude that a single-engine aircraft can reach and maintain in level flight. This altitude is lower than the absolute ceiling due to the limitations of having just one engine to provide thrust. Single-engine aircraft are designed to operate at lower altitudes for safety and stability.