An offer, together with acceptance and consideration, is one of the elements needed  to form a contract under US law.  The offer provides a counterpart  (sometimes called an offeree) with the power to accept a deal and to form an agreement.

To identify an offer  make sure that one party, the offeror, is unambiguously communicating his intention to enter into a deal if the offeree agrees.  If Mr. A offers $100 to Mr. B to paint his fence, this should be an offer because if B agrees, we would have an agreement to paint a fence.  On the other hand, if A is simply thinking of offering B $100, that’s not an offer, because it hasn’t been communicated.

Also, If Mr. A tells Mr. B that he’s thinking about hiring someone to paint his fence and would consider paying around $100, that’s also not an offer.  Mr. A sounds like he’s trying to negotiate with Mr. B. 

Below is a video on the offer.  I have more content up already on Udemy.