The withdrawal of an offer refers to the act of the offeror to cancel the offer before it becomes legally effective. The revocation of an offer refers to the act of canceling an offer after it has become legally effective and the offeror makes it lose its legal effect. The difference between the withdrawal of an offer and the withdrawal of an offer lies in:
 1. In terms of manifestation, the withdrawal of the offer occurs before the offer reaches (or just reaches) the offeree, while the withdrawal of the offer occurs before the offer has reached the offeree and the offeree has not yet sent a notice of acceptance. The essential difference between the two is that the former occurs before the offer becomes effective (or has just become effective), while the latter occurs after the offer becomes effective and before the offeree sends a notice of acceptance.
 2. The two types of situations in which the offer cannot be revoked should be accurately remembered. In particular, the offeree is required not only to "have reason to believe that the offer is irrevocable", but also to "have made preparations for the performance of the contract". The two parallel conditions are indispensable.
 [Legal Basis]
 Article 476 An offer may be revoked, except in any of the following circumstances:
 （1） The offeror expressly states that the offer is irrevocable by determining the time limit for acceptance or in other forms;
 （2） The offeree has reason to believe that the offer is irrevocable and has made reasonable preparations for the performance of the contract.