When buying or selling a home what is this item called an escrow deposit?

Whenever a buyer makes on offer to purchase a home one of the line items is an escrow deposit to made in say 1 day or 3 days etc...
This is the buyer's putting some money to be held in a third party escrow account.

A sort of good faith as the contract moves forward.

The amounts can very based on each situation.

Mark Stampini