Ghusl is the full ritual washing of the whole body required in Islam to remove a state of major ritual impurity and restore the purity necessary for prayer and other acts of worship. It is distinguished from the lesser ablution, wudu, which washes only certain parts of the body and suffices for minor impurity; ghusl is required after those events that bring major impurity, chief among them sexual activity, the completion of menstruation and of post-childbirth bleeding, and, as a duty falling on the community, the washing of the dead before burial. Without ghusl in these states the prayer is not valid, so the washing is the indispensable gateway back to worship.
The ritual has a prescribed form: it begins with the intention, the washing of the hands and private parts and the performance of wudu, and then the pouring of water over the entire body so that no part is left dry, the whole accompanied by the inward intention of purification. Beyond the obligatory occasions, ghusl is recommended before certain acts of devotion, before the Friday congregational prayer, before the two festival prayers, and before entering the state of consecration for the pilgrimage, so that the worshipper approaches these occasions in a state of heightened purity. The practice reflects the strong emphasis Islam places on ritual purity as the precondition of standing before God.