It is always preferable to have a will. A will states your preference as to the disposition of your estate. A will can and should be changed as your circumstances and preferences change. Even if you take measures to avoid probate, you should have a will as a back-up. A person who dies with a will is said to have died testate. A person who dies without a will dies intestate. In either case, the person who dies is called the decedent, and the property the person leaves at death is called the his or her estate.

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Wills, Trusts, Estates – Forum

Law Wiki: Wills and Trusts