zenki vs chuki

[Orcajin]

hey folks, just here asking a question or two

i've been reading a bit about my s13 on the internet
and i've heard there are two variants
zenki and chuki...
how wouold i be able to tell which variation my s13 is?
and is one considered first gen/second gen??
if anyone has a bit of info they could pass my way, then that'd be just swell

here is a pic of my s13, in case someone can tell just by the pic, if not, how would i be able to find out for myself??

thanks

==Orca