What is the difference between a revocable trust and an irrevocable trust? Is there an advantage to one form over the other?

The main difference between a revocable trust and an irrevocable trust is whether or not the settlor (i.e. trust creator) maintains any control or interest in the trust.  A revocable trust is a where the assets within the trust are still within the reach and control of the trust creator.  The individual who created a revocable trust maintains the ability to amend and the power of revocation.  The practical reality of this structure is that the settlor can revoke the trust at any time and will maintain ultimate control of the property held in the trust.  In contrast, an irrevocable trust is one where the settlor relinquishes all control of the trust and the assets contained within.  Once an irrevocable trust is made, the creator of the trust maintains no control, has no power to revoke, and has no claim of ownership in the trust property.  The benefits of an irrevocable trust are largely related to tax benefits for the settlor.  A revocable trust does not have the same tax benefits; however, the property within the trust is still within the control of the trust creator.  Historically, irrevocable trusts have the form of choice for charitable trusts and family wealth vehicles.