Written contracts may consist of a standard agreement or a letter confirming the agreement. In principle, a contract is concluded every time one company offers something to another and the offer is accepted. Think about the last time you accepted a job offer. The company offered you a job and you agreed, so a contract was concluded. Employment contracts are one of the most common types of legal agreements. Counter-offers: a counter-offer denies the initial offer. It modifies the initial offer and thus horrifies the person who makes the initial offer of any bond. For example, A made an offer to sell A`s car for $10,000.00. B offerS A$9,000.00. If A accepts this offer, B is required to purchase the vehicle at this price. A is not obliged to accept B`s offer and is not obliged to do so. A person who only carries out certain acts on the basis of a promise of another party may impose culpable Estoppels, a principle that a promise can be enforceable by law, even if the promise is made without formal consideration. .