Teacher Discussion Forums

This is a dictionary definition of 'BOOKS'.
'a bookmaker's record of bets accepted and money paid out'
I wonder what this 'bets accepted' means here.

Thank you.

A ‘bet’ is “an agreement between 2 persons or groups that the one who is proved wrong about the outcome of an event will give a particular thing or sum of money to the one who is proved right.”

Thank you very much, Buddhaheart.