Hadith

The Hadith (had-eeth) الحديث) is the collections of sayings, teachings, actions, approval, & disapprove of Prophet Muhammad. This is called the Sunnah (tradition).

Sahih
A sahih hadith is a hadith with a continuous isnad, has trustworthy narrators who have trustworthy memory from similar authorities free from irregularities in text and defects in isnad.

Mutawatir
The conditions for mutawatir hadiths is:
 * 1) at least 4 different narrators of this hadith.
 * 2) It is impossible for the narrators to have lied.
 * 3) Must have a hadith that is similarly narrated from other narrators.
 * 4) Their ahadith which narrator narrates must rely on mind and senses, not only mind because the mind could be wrong.

Hasan
Hasan hadiths are hadiths which are not weak but don't meet the standard of weak ahadith. The hadith must be free from irregularities from ahadith.

Daif
Daif hadiths are hadiths with discontinuity in isnad of hadith. The weak (da'if) hadith could be Mursal, Mu'alliq, Mudallas, Muqafi, or Mudal

Da'if is also for hadith with narrator who has a disparaged character (ex: making constant mistakes, being a liar, opposing stronger narrator of similar hadith, etc.)

Maudu
Maudu (fabricated) hadiths are hadiths which are fabricated. A hadith is maudu if the narrator is a known liar or the hadith goes against the norms of the saying of the Prophet (peace and blessings of Allah be upon him.

Sunni
The Sunnis believe in following the sunnah (tradition) of Prophet Muhammad. They have books of the sayings and actions of Muhammad called ahadith. There are the six major books (al-kutub al-Sittah). The six major collections are by: Bukhari, Muslim, an Nasa'i, at-Tirmidhi, ibn Majah, and Abu Dawud. In Sunni Islam it is required to follow the Quran and Sunnah.

Shia
Shias believe many hadiths proves thier believe of Walayat (leadership) of Ali such as, the Hadith of the Pond of Khum, Hadith of two weighty things, Hadith of the Pen and Paper, Hadith of the Cloak, and Hadith of invitations of Families. The Shias like Sunnis have hadith except the Shias don't find some of Muhammad's companions to be trustworthy. For this reason, Shia have their own hadith collections seprate from Sunni collections. Their hadith contains attributed sayings of the Shia Imams. The Shia hadiths are each induvidually examined as Hadith are collected by fallible people and have some mistakes and authentic hadith. Shia believe the only sahih book is the Qur'an.

Ibadi
Ibāḍīs accept as authentic far fewer hadīth than do Sunnīs, and some of those accepted by Ibāḍīs are rejected by Sunnīs. Ibāḍī jurisprudence, naturally, is based only on the ḥadīth accepted by Ibāḍīs. Several of Ibāḍīsm's founding figures were noted for their ḥadīth research, and Jābir ibn Zayd is accepted as a reliable narrator by Sunnī scholars as well as by Ibāḍī ones.

The principal ḥadith collection accepted by Ibāḍīs is Musnad al-Rabī' ibn Ḥabīb, as transmitted by Abū Ya'qūb Yūsuf ibn Ibrāhīm al-Warijlanī. Ibāḍī jurists use the rules set by Abū Ya'qūb al-Warijlanī to determine the reliability of a ḥadīth. These are largely similar to those used by Sunnīs.

Ibāḍī jurists criticize some of the Companions, believing them corrupted after the reign of the first two caliphs. Still, they accept hadith narrating the words of the companions as a third basis for legal rulings, alongside the Qur'an itself and ḥadith citing Muhammad.