Al-Ghusl is an Arabic parlance which means ritual bath i.e washing the whole body. It is therefore an Islamic form of purification, by washing the whole of the body from impurity. Al-Ghusl is referred to as major purification, just as ablution is known as the minor purification. Allah is pure and will accept no form of worship that has atom of impurity. Any condition that requires performance of Al-Ghusl is called major impurity. Al-Ghusl purifies the body and soul for the acceptance of one's worship by Allah.
Al-Ghusl is performed in some of the following cases (1) The release of semen as a result of masturbation, sexual interaction, dreams, touching the opposite sex and any other situation that can lead to the release of semen to the body
(2) Death of a muslim
(3) A muslim must purify himself or herself after sexual intercouse, and in the case of the male, purification is obligatory whether or not there was a release of semen.
(4) Women are to purify themselves after their menstrual periods
Allah says in the Quran, "If you are polluted, purify yourselves."