A more thorough explanation:

A revocable living trust is a type of trust that is created during the lifetime of the person who sets it up, known as the settlor. The settlor has the power to change or end the trust at any time, and can also recover the assets that were placed in the trust. If the settlor does not reserve the power to revoke the trust, then the trust is considered irrevocable.

For example, let's say that John sets up a revocable living trust and places his house and savings into the trust. He reserves the right to change or end the trust at any time. If John decides to revoke the trust, he can take back his house and savings. However, if John did not reserve the power to revoke the trust, then he would not be able to change or end it.

It's important to note that the rules for revocable living trusts may vary depending on the jurisdiction. For instance, some states may require certain formalities to be followed in order to revoke a trust, while others may not.