Each week a guest , called a `` castaway '' during the program , is asked to choose eight pieces of music , a book and a luxury item that they would take if they were to be cast away on a desert island , whilst discussing their lives and the reasons for their choices .
Each week a person ( called a `` castaway '' ) is asked to choose eight pieces of music , a book and a luxury item that they would take if they were to be cast away on a desert island ( an island that is not lived on by humans ) . They discuss their lives and the reasons for their choices .