What's the purpose of A and B partition slots if both are flashed?

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

Thread AB slot issue, TWRP only on one unrooted rom on other Can't mount from TWRP TWRP is on slot B but not slot A I can only reboot to system from TWRP

slot pay by phone bill My device is indeed in a temporary TWRP flash

gnome slot Yes, they provide a backup in case something goes wrong However, primarily it is used to perform seamless updates This means an update will