Monopoly was a game where you had to try to acquire as much property as possible while navigating your "piece" around the board.
If someone landed on a property that you owned, they had to pay you some money.
I remember a few of the place names from the original game, like Old Kent Road, Park Lane, and Mayfair, and a couple of stations but that's about it nowadays.
There were also "chance" cards and "community chest" cards that could be either good or bad. You would either win a beauty contest and get some money from the bank, or you would be put into jail!
I always made my Dad be the banker, so he couldn't win. I'd just distract him by pinching money, and he'd forget what he was doing!