The Earnest Money Deposit
Explanation in full
As with any endeavor, money talks when buying a house. Your earnest money deposit tells the seller that you are serious.
When you submit a written offer to a seller, you generally are required to include a deposit in the form of a personal check, cashier's check or cash. That deposit is called "earnest money" and it signifies to the seller that you are ready and willing to purchase his or her home.
How much earnest money should you give the seller? A good rule of thumb is 1% of the offered price, but the custom may differ in your part of the country, so consult with your agent.
The listing broker will hold your money in a special trust account until the transaction closes, at which time it will be applied to your down payment. If the seller doesn't accept your offer or if some condition of the contract is not satisfied, the listing broker will refund your money.
One word of caution: if you have a meeting of the minds with the seller and enter into a binding contract, you will be required to perform. Should you decide to walk away, you will lose your earnest money and perhaps worst.