in the battle with Muslima the liar many huffaz were martyred,. hazrat umar realized the need of preservation of holy Quran and he suggested this to abu bakr, Hazrat abu bakr appointed zaid bi tibbat to constitute a board of uhffaz for compilation, finally they have done and made three copies given to i hazrta abu bakr, one hazrat umar, and one hazrat hafza,
with the expansion and spread of islam in the non-arab areas. there was a problem in reciting of verses, Hazrat usman also made a committee, which took copy of Hazrat Hafza and made more copies after this hazrat Usman sent these all copies to all the centers of muslim world

i think now it is quite clear for you people

stay blessed