In PHP, what is a Tick?

Question

I know that Ticks are not PHP specific and are somewhat related to timing and/or number of operations, but I lack all the understanding that would otherwise allow me to work with them.

Can someone please explain to me what ticks are / do in a simple fashion?

Answer 1

I found a decent explanation here. I have used them in writing daemons.

I think declare() might be planned for deprecation. I know it was at one point.

EDIT: It was the ticks directive that was planned for deprecation.