"Offer" and "acceptance" are neccessary to create a binding obligation between parties. An "offer" is a proposition to enter into a contract; an "acceptance" is a proper manifestation by the party to whom the offer is made of his assent to it. Both the offer and its acceptance are necessary. In many cases it is necessary to analyze carefully the negotiations between the parties to discover whether there have been an offer and an acceptance, especially when the negotiations have continued over some time and there has been a variety of terms proposed. The reason is that it would be unfair to bind one party to a transaction unless the other party had had the same thing in mind. It is necessary that the minds of the parties shall meet and that they shall agree upon all material parts of the alleged agreement. Yet if the party who made the offer (the "offeror") had made his offer in definite terms and had taken reasonable steps to inform the other party (the "offeree") of them, then the law presumes that the second party in accepting the offer accepted on those terms, and a "meeting of the minds" is presumed to have occurred. There must be serious intention to enter into an agreement. A jesting agreement is not binding, even though the parties go through the form of making a contract, if they had not intended it to stand. It is dangerous, however, to make offers or acceptances in jest, for if the joke is so well carried out that it is likely to deceive, one of the parties may enforce it in court if he alleges that he took it seriously.