Existance is the second currency. It is earned by prestiging existivity. It produces existivity.
Existance produce existivity at the rate of 0.01 per second.
After gathering 10 existances, you'll see a new button but it is unavailable. You'll be able to do it with 16 existances, and you must do it because you won't be able to prestige existivity for more existances. Doins so will reset existivity and existances, but you'll get a second of experienced time.