What is the authenticity of the hadith: "My Ummah will be divided into seventy-odd sects, one of which will be saved," and what are examples of these sects?

The Hadith that mentions the division of the Ummah into seventy-three sects, all of them in Hellfire except one, is one of the miracles of the Prophet, peace and blessings be upon him, because it is a report about an unseen matter that has already occurred. The Hadith indicates that this Ummah resembles those who preceded it, as it added one sect to the seventy-two sects into which previous nations divided. The saved sect is the one that was preserved from resembling the Jews and Christians; these are the People of the Sunnah and the Community (Ahl al-Sunnah wal-Jama'ah) who followed the methodology of the Prophet, peace and blessings be upon him, and his companions, and among them are the Imams of guidance. As for the misguided sects, such as the Mu'tazilah, the Khawarij, and the Jahmiyyah, their deviation is in matters of creed and fundamental principles of religion, and not in matters of jurisprudential branches.