Which kernel should I use?

[Dennis Wicks]

I notice that there is available two different kernels;

        linux-image-4.9.0-8-686-pae

and

        linux-image-4.9.0-8-rt-686-pae

I am running on a Pentium 4.

Which one of these should I be using? And just for
curiosities sake, why?

TIA!
Dennis