What is the difference between offer and Invitation to offer?

Offer

1. Offer means a proposal by a person in which he makes his willingness to enter into a legally binding contract for some conside­ration.

2. An offer is made with the object of getting consent of the offeree.

3. An offer can be accepted by the offeree.

4. An offer when accepted becomes an agreement.

Invitation to Offer

1. An Invitation to offer means an intention of a person to invite others with a view to enter into an agreement.

2. An invitation to offer on the other hand is made with

3. An invitation to offer cannot be accepted by the person to whom it is made.

4. An invitation to offer cannot be accepted at all.