| A | B |
| contracts | agreement that is legally effective and enforceable in court |
| offeror | The person who makes the offer |
| offeree | Party to whom an offer is made |
| offer | proposal by an offeror to do something, provided the offeree does something in return |
| acceptance | affirmative response necessary to transform an offer to a contract |
| bilateral contract | Binding agreement created by an offer that is accpeted by a promise of performance |
| counteroffer | Response by offeree, with new terms, which ends the original offer |
| firm offer | Signed writing by a merchant stating how long it is to stay open |
| mirror image rule | Requirement that the terms in an acceptance exactly match the terms in the offer |
| option | contract to leave an offer open for a period of time in exchange for other consideration |
| revocation | offeror's withdrawal of an offer before it is accepted |
| unilateral contract | offeror promises something in return for the offeree's performance and indicates that this performance is the way acceptance must be made |