The Quran is the word of Allah, the Almighty.
Sunnah is the action & words (sayings, also called Hadith or hadees) of Prophet Mohammad (peace be upon him).
The collection of the Hadith is done by religious men like Bukhari, Abu Dawood…..
While there is only ONE version of the Quran–unchanged, unaltered since the time it was revealed to the Prophet Mohammad (peace be upon him), the hadith, however, may need to be checked for authenticity, as they were collected by humans.
Nevertheless, the above-mentioned are believed to be the most accurate sources of Hadith.
God bless you for asking