Question: how are tom riddle and voldemort related?
Answer: Harry and Dumbledore study Lord Voldemort's early years by viewing donated memories in Dumbledore's Pensieve. Voldemort's mother, Merope Gaunt, is Salazar Slytherin's direct descendant, and his father is Tom Riddle, a Muggle. During this time period, Voldemort is known by his birth name, Tom Marvolo Riddle.