acceptance
The seller's written approval of a buyer's offer.

addendum
An addition or change to a contract.

backup offer
A secondary bid for a property that the seller will accept if the first offer fails.

contingency
A condition specified in a purchase contract, such as a satisfactory home inspection.

contract to purchase
A contract the buyer initiates which details the purchase price and conditions of the transaction and is accepted by the seller. Also known as an agreement of sale.

counteroffer
A response to an offer.