Praise be to Allah.
There are two kinds of ghusl from janaabah – sufficient and complete.
Sufficient ghusl means that you rinse your mouth and nose, then you wash your entire body with water, even if that means plunging yourself into deep water in one go. Complete ghusl means washing your private parts and anywhere else that is contaminated with traces of impurity, then you do full wudoo’, then you pour water over your head three times, making sure that it reaches the roots of the hair. Then you wash the right side of the body then the left side.