A Trust Agreement is nothing more than your written instruction directing someone (the "trustee") on how to manage your property (the "corpus") for the benefit of your heirs (the "beneficiaries").
There are four components to a trust: (1) the settlor (the person who creates the trust), (2) the trustee (the manager of the trust), (3) the beneficiary (the entities or individuals receiving benefits from the trust), and (4) the corpus (the trust property/assets).
TIP: Each component is necessary to create a valid trust. For example, a trust without a corpus may not be valid. It is for this reason that most are funded with something at the time it is created, even if it is only $1.00.
A Trust is often an integral component of an estate plan. Settling upon the type of trust best suited for your particular estate plan should be based on consideration relating to your particular goals and objectives.