A simple definition of a Trust is one party (the Trustee) holding assets which belong to another party (the Grantor) for the benefit of another party (the Beneficiary). In the standard Revocable Living Trust usually at the establishment of the Trust, one party may be all three, the Grantor, Trustee, and Beneficiary. While the Grantor is alive, the Grantor has complete control and acts as Trustee, and the Grantor is also the Beneficiary.
Upon the death of the Grantor, a Successor Trustee takes over and administers the Trust for the benefit of the Beneficiaries. The Trust sets forth the terms of the distribution of your assets.