The three obligations are mouth rinsing, nasal rinsing, and washing the required entire body. Al-Shafi‘i differs by treating the first two as Sunnah.
The Sunnah method includes beginning with cleaning, making wudu, pouring water over the body three times, and washing the feet at the end if needed. A woman may keep her braids tied when water reaches the hair roots. The causes that make ghusl obligatory are a separate next topic.