Most likely it means the process whereby sound fonts are prepared for synthesisers:
(1) You record every note of the instruments's range, one at a time, on a real instrument, digitising each one and storing it separately
(2) You then arrange that when you trigger a note e.g. by playing it on a keyboard, the recorded sound of the instrument playing that note is played back.

To get more realism, it's common to record each note in several different styles and loudness levels, and clever algorithm for picking or blending the right recorded versions of each note depending on how it's played, all to make it sound more realistic.

All good digital pianos use the recorded sound of a real piano, for example.

Anahata