Definitions of inter vivos trust
a written declaration and contract in which you state that you are transferring your property into an inter vivos trust for the benefit of yourself during your lifetime (lifetime beneficiary) and then for the benefit of your heirs following your death (remainder beneficiaries); a trust that begins during the lifetime of the trustor or settlor (=the person creating the trust) as opposed to a testamentary trust (= a trust created by a will that begins following the death of the will's writer)
The main advantage of an inter vivos trust is the avoidance of probate (=the legal process of deciding whether or not a document, especially a will, is valid).