A more thorough explanation:

Definition: Reversion is a type of future interest that the grantor (the person who transfers ownership of a property) keeps for themselves. It comes into effect after the end of a fee tail estate, life estate, or term of years. It is different from remainders, which are future interests that are given to someone else.

Example: Let's say that John owns a piece of land and he wants to transfer ownership to his daughter, Sarah. However, he wants to make sure that he still has some control over the land after he gives it to her. So, he decides to give her a life estate, which means that she can use and enjoy the land for the rest of her life. But when she dies, the land will go back to John. This is an example of a reversion.

Another example: Mary owns a rental property and she wants to sell it to her son, Tom. However, she wants to make sure that if Tom ever decides to sell the property, it will go back to her instead of someone else. So, she decides to give him a term of years, which means that he can own and rent out the property for a certain number of years. But when the term is up, the property will revert back to Mary. This is another example of a reversion.

These examples illustrate how a reversion works. It is a way for the grantor to keep some control over the property even after they have transferred ownership to someone else. It can be useful for estate planning or for situations where the grantor wants to make sure that the property stays in the family.