Wills and trusts are different ways of disposing of real and personal property. Key differences include who has title to the property, when they become effective and the parties involved.
A will describes how the assets of a person, called the testator, should be distributed when the testator dies. The testator makes what is called a testamentary gift directly to one or more beneficiaries. After the will goes through probate, the beneficiary has legal title to the property.
Unlike a will, a trust is created when the property owner--called a settlor--transfers legal title to a trustee who manages the property for a beneficiary. The property that is being transferred is called the trust res. Unlike the beneficiary of a will, the beneficiary of a trust does not obtain title to the entire trust res all at once.
According to the 'Lectric Law Library, a will is only effective after the testator dies. A trust is effective whenever the settlor wants. If the trust is created during the settlor's life, it is called an inter vivos trust. If the trust is created in a will, it is called a testamentary trust.