"A will or testament is a legal document that expresses a person's (testator) wishes as to how their property (estate) is to be distributed after their death and as to which person (executor) is to manage the property until its final distribution. For the distribution (devolution) of property not determined by a will, see inheritance and intestacy.
Though it has at times been thought that a "will" historically applied only to real property while "testament" applied only to personal property (thus giving rise to the popular title of the document as "last will and testament"), the historical records show that the terms have been used interchangeably. Thus, the word "will" validly applies to both personal and real property. A will may also create a testamentary trust that is effective only after the death of the testator."
"Probate is the judicial process whereby a will is "proved" in a court of law and accepted as a valid public document that is the true last testament of the deceased, or whereby the estate is settled according to the laws of intestacy in the state of residence of the deceased at time of death in the absence of a legal will.
The granting of probate is the first step in the legal process of administering the estate of a deceased person, resolving all claims and distributing the deceased person's property under a will. A probate court decides the legal validity of a testator's (deceased person's) will and grants its approval, also known as granting probate, to the executor. The probated will then becomes a legal instrument that may be enforced by the executor in the law courts if necessary. A probate also officially appoints the executor (or personal representative), generally named in the will, as having legal power to dispose of the testator's assets in the manner specified in the testator's will. However, through the probate process, a will may be contested."
(from Wikipedia)