Let's take flight simulation as an example. If you're trying to train a pilot, you can simulate almost the whole course. You don't have to get in an airplane until late in the process.
-- Roy Romer
   
Roy Romer   Name:
Roy Romer
Type:
Politician
Nationality:
American
Birth:
October 31, 1928
https://www.nutquote.com/quote/Roy_Romer