where does today Quran variants come from?

where does today Quran variants like khalaf, hafs, warsh, etc... come from? do they go back to the prophet(pbuh) and it's the different way the Quran was originally revealed with or they go back to Uthman(ra) Quran as Uthman(ra) burned those different variants and these different came to place where Arabic diacritical marks had to be added to the Quran?