Denotation for the community of Muslims, that is, the totality of all Muslims.
The term comes from a word that simply means ‘people’. But in the Koran, the word is used in several senses, but it always indicates a group of people that are a part of a divine plan and salvation. There is even an example of the word being used for an individual, Abraham (16,120).
Umma used for a group is often to be understood as confined by ethnicity or linguistics. But as we see it in the Koran, this situation was not original:
Koran sura 10: Jonah
20 People were but one nation once, then they disagreed; and had it not been for thy Lord’s word already passed, there would have been decided between them that concerning which they disagreed.
It appears that in the early days of Islam, umma was used for the population of Mecca, but with the development of Islam, the umma of Muhammad changed to become believers, and therefore excluded Meccans that had not converted.
The umma term has without being a central theological concept, been crucial to the Muslim understanding of unity.