Plain English Meaning
The strip of ground (or other surface) that aircraft physically land on. Its direction tells pilots which way to fly the traffic pattern and which runway to use.
Full Definition
The portion of an airport's runway, strip, or other prepared area that is used for the actual touchdown and rollout of an aircraft during landing. The orientation of the landing surface determines the direction aircraft fly the traffic pattern and the runway in use.
Context Anchor
In a standard airport traffic pattern, the pilot flies the pattern in relation to the landing surface and lines up with it on final approach.