Other forms: escrows
If you buy a house, you'll have to put money in escrow, which means you give it to a third party (like a bank), while the seller actually brings the deed and signs it over to you.
The word escrow comes from the Old French escroue meaning "scrap, roll of parchment." Think of an escrow as a deed rolled up and delivered to a trusted person who hangs onto it, only giving out the money on the deed after the person who's supposed to get it does whatever he agreed to do. It's a safe way to do business, and prevents sellers from running off with your money before they've given you what you bought.