What are some famous trios in mythology and what roles do they play in their respective stories?

Some famous triOS in mythology include the Greek Fates (Clotho, Lachesis, and Atropos) who control human destiny, the Norse Norns (Urd, Verdandi, and Skuld) who determine fate, and the Hindu Trimurti (Brahma, Vishnu, and Shiva) representing creation, preservation, and destruction. These triOS play crucial roles in shaping the course of events in their respective mythologies.