What are the pillars of wudhu?

The pillars of wudhu (ablution) in Islam are essential acts that must be performed for the ritual to be valid. They include the intention (niyyah) to purify oneself, washing the face, washing the forearms up to the elbows, wiping the head, and washing the feet up to the ankles. Each of these acts must be performed in a specific sequence to fulfill the requirements of wudhu. Omitting any of these pillars invalidates the ablution.