A more thorough explanation:

An offer is a promise to do or not do something in exchange for something else. It must be clear and delivered in a way that would make a reasonable person believe that accepting the offer would create a binding contract.

1. A store advertises a sale on televisions for $500. This is an offer because it is a clear promise to sell a television for a specific price.

2. A person offers to mow their neighbor's lawn for $20. This is an offer because it is a clear promise to perform a service in exchange for payment.

3. A company sends a letter to a job applicant offering them a position with a salary of $50,000 per year. This is an offer because it is a clear promise to hire the applicant at a specific salary.

These examples illustrate the definition of an offer because they all involve a clear promise to do or not do something in exchange for something else. They are also delivered in a way that would make a reasonable person believe that accepting the offer would create a binding contract.