What is AB partition and How to flash roms in it

What's A B Partition Android System & Seamles System Updates, TWRP Slot A Slot B

B partition ONLY)

iconic gaming slot if you're on partition slot A then the update will be installed to Slot B Unlock

smeg long slot toaster I'm working with Android 9 Pie and I have one slot rooted and the other is not My reasoning to have my phone this way is