How much graphic quality can IOS support?

Hi guys,

I am just starting with Unreal Engine and never produced any game before.
But there are some questions that I would like to know before starting a project, to avoid any big mistakes and reworking.

What should I have in mind when development for IOS in matters of graphics ?
I mean what is the actual power of IOS for games today ? are there limitations that I should take in account regards polygon count, lighting, quantity of objects in the scene, particles etc.
Any recommendations?

I imagine that IOS is still far from supporting graphics as high as PC and Playstation 4 games ?

Sorry if any of my questions sound silly in anyway. But I am really just starting with games and I am trying to find as much information as I can on google, but sometimes I cannot find
a clear answer for everything. Please someone give me some advices about it.

Thank you.

do you have an example of what you want to achieve?

these links should help