Alan Turing was a pioneering computer scientist and mathematician in the early 20th century. He played a pivotal role in cracking the German Enigma code during World War II, which helped the Allies win the war. Turing is considered the father of computer science and his conceptualization of a universal machine laid the foundations for modern computers. However, he was prosecuted for his homosexuality in 1952 and died by suicide at age 42. His contributions helped enable future technologies like the iPhone and iPad.