Each printed edition of the Qurʾān follows a particular Qirāʾah.
There are seven readings of the Qur’an that are considered authoritative, another 3 that are accepted by the majority of scholars, and another 4 that some accept and others reject as unconfirmed.
As an example of the differences between two readings, in 1:3, some readings have mālik, while others have malik. Both mean owner or possessor?
Another example, in 1:6, some readings have ṣirāṭ where others have sirāṭ. Both mean path or way.
main one is "hafs"
You get different qira'at, styles of recitation. The most popular being Hafs and Warsh. You get the riwayah of Asim through Hafs. You get the riwayah Nafi' through Warsh. So they are usually called Hafs and Warsh. It's the recitation of famous reciters from the Salaf that have been preserved.