What do the terms Grantor Trustee and Beneficiary mean and what are their responsibilities?

The Grantor in this case is you, it is the person who sets up the trust. It is generally also the person who funds the trust. The Trustee is the person who is responsible for administering the trust, investing the assets and handling any of the administrative duties which need to be performed. Finally the Beneficiary is the person who benefits from the trust. This is the best position to be in with any type of trust. Normally a Revocable Living Trust is set up such that you take all three of these duties. You are the person who sets up the trust, you are the trustee who administers the trust during your lifetime and you are the one who is paid the income and benefits as a beneficiary of the trust during your lifetime.