Private business dealings based on supply and demand define?

So here the interplay of supply and demand influences the dealings of the private business which means that it's not centrally decided but rather market analysis is done to determine what is needed.

So I would say the best answer is: market forces!

If the head of the business was not looking to the market, but rather making central decisions, we could call it "central planning "

in his book, the riddle of the rosetta stone, james giblin talks about how there was a young british polymath and physician named thomas young who made a lot of advances on the deciphering of the rosetta stone. he says that even though young made a lot of mistakes because he was working under false assumptions, he also made huge contributions like deciphering three out of the seven symbols (more than anyone else before him). young published his findings and continued his good work but he wasn't able to progress much further due to some unfavorable situations, he still laid the basis for many other scholars and of course for the man who has been generally known to have deciphered it, jean-françois champollion

it was on the rise and doing very well and would continue to do well until the great depression from 1929-1939