غسل، در لغت به معنای شستن است و در اصطلاح به مجموعهای از اراده قلبی و اجرای عملی در خصوص شستن بدن گفته میشود.
غسلها بر پایهٔ حکم شرعی به دو دسته تقسیم میشود:
هفت نوع غسل واجب وجود دارد که خود به دو گروه اصلی تقسیم میشوند:
غسلهای واجب مشترک زنان و مردان[ویرایش]
غسلهای خاص زنان[ویرایش]
غسلهای مستحب بسیاری وجود دارند. از جملهٔ غسلهای مستحب میتوان به موارد زیر اشاره کرد:
غسل واجب یا مستحب را (به جز غسل میت) به دو صورت میتوان انجام داد:
در غسل ارتماسی باید بدن پاک باشد ولی در غسل ترتیبی پاک بودن تمام بدن لازم نیست و اگر تمام بدن نجس باشد و هر قسمتی را پیش از غسل دادن آن قسمت آب بکشد کافی است.
تعرف غسل ترتیبی[ویرایش]
در غسل ترتیبی باید به نیت غسل، نخست سر و گردن، و سپس نیمهٔ راست بدن از گردن تا کف پا و دست راست و بعد نیمهٔ چپ بدن از گردن تا کف پا و دست چپ را بشوید. و دیگر تمام
تعرف غسل ارتماسی[ویرایش]
در غسل ارتماسی باید آب در یک لحظه، تمام بدن را بگیرد. پس اگر به نیت غسل ارتماسی در آب فراوانی مانند استخر فرو رود.
بگیرد و اگر آب برای وضو نیست یک تیمم بدل از وضو هم بگیرد. و در هر صورت برای نمازهای بعدی مادامی که عامل آن غسل تکرار نشدهاست (مثلاً دوباره جنب نشدهاست) و آب هم برای غسل پیدا نکردهاست یا وضو میگیرد و یا در صورت نبودن آب تیمم بدل از وضو میکند.
Ghusl (Arabic: غسل Ġusl , IPA: [ˈɣʊsl]) is an Arabic term referring to the full body ritual washing ablution required, if the adult loses the state of body cleanness, in Islam for adults prior to ablution (wudu وضوء) for various rituals and prayers. Ghusl is mandatory for any adult Muslim after having sexual intercourse, orgasmic discharge (e.g. semen), completion of the menstrual cycle, giving birth, and death by natural causes.
Islam also recommends (i.e. it is mustahab) the performance of the full ablution before the Friday sermon prayer and Eid prayers, before entering the ehram, in preparation for hajj, after having lost consciousness, and after formally converting to Islam. Shia Muslims also perform the ablution before Namaz-e-tawbah.
Ghusl is allowed with the following types of water
Ghusl is not allowed with the following types of water
The acts of Ghusl
"O ye who believe! Approach not prayers with a mind befogged, until ye can understand all that ye say,- nor in a state of ceremonial impurity (Except when travelling on the road), until after washing your whole body. If ye are ill, or on a journey, or one of you cometh from offices of nature, or ye have been in contact with women, and ye find no water, then take for yourselves clean sand or earth, and rub therewith your faces and hands. For Allah doth blot out sins and forgive again and again."
Farā'id of Ghusl
There are three fard (obligatory) acts. If one of these acts is omitted, it must be returned to and then completion of the successive acts are to be performed.
Sunnah of Ghusl
Sunni school of thought 
If, after Ghusl, one recalls that a certain portion of the body is left dry, it is not necessary to repeat the Ghusl, but merely wash the dry portion. It is not sufficient to pass a wet hand over the dry place. If one has forgotten to rinse the mouth or the nostrils, these too could be rinsed when recalled after Ghusl has been performed.
The following ahadith describe how ghusl should be performed by Sunni Muslims.
In another hadith, ibn Abbas stated that Maimuna said that The Messenger of Allah was given a towel (after ghusl), but he did not rub his body with it, but he did like this with water (i.e. he shook it off). In addition, ibn Abbas recorded the following hadith on the authority of his mother's sister.
Similarly, Muhammad ibn Saalih al-Uthaymeen said, "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 head, 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."
Shia school of thought 
There are two methods of performing ghusl. One is known as ghusl tartibi, and the other is known as ghusl irtimasi.
"Ghusl tartibi" means an ordinal bath, performed in three stages.
After washing away the najasat (e.g., semen or blood) from the body and after niyyat, the body has to be washed in three stages: First, head down to the neck; then the right side of the body from the shoulder down to the foot; and lastly, the left side of the body.
Each part should be washed thoroughly in such a way that the water reaches the skin. Special care should be taken while washing the head; the hair should be combed (e.g., with your fingers) so that water reached the hair-roots. While washing the right side of the body, some part of the left side must be washed too, and also, while washing the left side of the body, some part of the right side must be washed.
"Ghusl irtimasi" means a bath involving immersion of the whole body in the water. It is needless to say that such a ghusl can only be done in a body of water, e.g., a pool, river, lake or sea. After washing away the semen or blood from the body and after niyyat, the whole body should be completely immersed in the water all at once, not gradually. One has to make sure that the water reaches all parts of the body, including hair and the skin under it.
However, ghusl tartibi is preferred to ghusl irtimasi.
Recommendable acts of Ghusl
What has been mentioned above are the wajib acts of ghusl; here we shall explain the things which are recommendable (mustahab, sunnat) during the ghusl. These recommendable acts are five:
'Ubaydullah al-Halabi narrates that someone asked Imam Muhammad al-Baqir (a.s.) about a man who performs ghusl and then finds some (doubtful) drops (on his penis) while he had already urinated before performing the ghusl. (That is, should he consider the drops as urine or semen?) The Imam said, "He will just have to do wudu (for hi s salat). But if he had not passed urine before the ghusl, then he must repeat the ghusl." (Wasa'il, vol. 1, p. 517. )
This rule of istibra' applies only to men. Sulayman bin Khalid asked Imam Muhammad al-Baqir (a.s.) about a man who became ritually impure because of sexual intercourse and then performed ghusl without urinating. Then some drops came out of him . The Imam said, "He must repeat the ghusl." Sulayman: "What if similar drops come out of a woman after she has performed ghusl?" The Imam said, "She does not have to repeat the ghusl . " Sulayman: "What is the difference between the two?" The Imam said, "(A woman does not have to repeat ghusl janabat) because what comes out of her is certainly from the (remnants of the) discharge of man." (Wasa'il, vol. 1, p. 482.)