Britannica Concise Encyclopedia:

Sunnite
Larger of the two major divisions of Islam, comprising 90% of the world's Muslims.

Sunnites regard theirs as the mainstream and traditionalist branch of Islam, as distinguished from the minority branch, the Shīites. Sunnites recognize the first four Umayyad caliphs (see Umayyad dynasty) as Muhammad's rightful successors. Because the Sunnites understood Muhammad's theocratic state to have been an earthly, temporal dominion, they were willing to accept unexceptional and even foreign caliphs, provided order and religious orthodoxy were maintained. Sunnite orthodoxy emphasizes consensus based on the views and customs of the majority of the community, thereby enabling them to incorporate various customs and usages that arose historically but that had no roots in the Qurān. Sunnites recognize the six authentic books of the Hadīth and accept the four major schools of Islamic law. In the early 21st century, Sunnite Muslims numbered about one billion.