Alaa M. answered • 08/01/19
Masters in Near Eastern & Judaic Studies
There is really only one Quran. There are ten accepted "readings" (qira'at) based on seven "letters" (ahruf). What that means is that there are simply 10 styles of reading and reciting the Quran based on variations in some of the lettering of the words which only very rarely affect the meaning or interpretation of a given verse. All ten readings are canonical and accepted as valid, even though the Hafs transmission is the most dominant one in the Sunni world. Some readings have died out and only experts know them. All ten readings were transmitted orally from generation to generation by the sahaba (companions). The variation in the qira'at is attributed to the variance in the language and pronunciation of the different tribes of Arabia. They are organic variations rather than artificial additions. Uthman (raa) has no direct role in this since the qira'at are transmitted orally - and so is the text of the Quran in general. The written book that Abu Bakr (raa) compiled and then Uthman (raa) commissioned writing several copies was merely a tool for the preservation and teaching of the Quran. Uthman (raa) grew concerned with the spreading of Islam that the Quran would be dispersed and so sent copies approved by the sahaba, who knew the Quran by heart, to the different governorates under his rule.
For more on the Quran and the history of its preservation, I highly recommend this book by Ingrid Mattson called The Story of the Quran: https://books.google.com/books?id=4YQdwqQaCvEC&printsec=frontcover&dq=books+the+story+of+the+quran&hl=en&sa=X&ved=0ahUKEwj5q9Spr-DjAhWLylkKHRdCDx4Q6AEIMzAC#v=onepage&q=books%20the%20story%20of%20the%20quran&f=false
Also, here's an example of a reciter (Sheikh Abdul-Baset Abdul-Samad) reciting the same verse with 7 qira'at: https://www.youtube.com/watch?v=UNgzlqI4JYI
