“Last Will” and “Last Will & Testament” are often used interchangeably to refer to the same document.
A last will is a legal document that outlines your instructions for what should happen upon your death. In your last will, you can specify gifts of things you own, who you would like to care for your minor children (if you have them), and what you would like as a final resting place for your body and any end-of-life ceremony requests.
A last will and testament is the exact same thing. The “testament” in the title simply refers to the act by which a person determines the distribution of his or her property after death.