What is a Will? A Will, also known as a “Last Will and Testament” is a written, legal document prepared and signed by a person - called a testator if male, or testatrix if female - stating what happens to their property, and who manages it, upon their death. The person managing the property is called the executor if male, or executrix if female. This person may also be called the estate trustee. More than one person can be appointed to do this.