There are many different sects in Islam, and this goes clearly against Islamic teachings. Allah says in the Quran, “And hold firmly to the rope of Allah and do not be divided. Remember Allah’s favor upon you when you were enemies, then He united your hearts, so you—by His grace—became brothers” (Quran 3:103). However, this raises the question: how does one know which sect in Islam is the right one? The Prophet Muhammad PBUH clearly answered this in a hadith where he said, “’The Jews split into seventy-one sects, one of which will be in Paradise and seventy in Hell. The Christians split into seventy-two sects, seventy-one of which will be in Hell and one in Paradise. I swear by the One Whose Hand is the soul of Muhammad, my nation will split into seventy-three sects, one of which will be in Paradise and seventy-two in Hell.’ It was said: ‘O Messenger of Allah, who are they?’ He said: ‘The main body'” (Sunan Ibn Majah 3992). In another narration, He PBUH said, “Those who will remain on the path which I and my companions are on today.” Therefore, it is clear that he is talking about the Sunnis, or those who follow the sunnah of the Prophet Muhammad PBUH. The Sunnis make up about 90% of the Muslim population, which is clearly the vast majority of Muslims. However, the name Sunni was given to clarify and distinguish between all the other sects, but one should just call himself a Muslim, because that is what the Prophet Muhammad PBUH and his companions were called.
And Allah knows best.