What exactly google Penguin 2 update says?

I am new in this internet marketing sector, I was wondering to learn SEO . But i have heard google changes their algorithm ,

can any one plz explain what google penguin says, what to do and what is forbidden ?
Thanks

There has been a lot of discussion on the forum about this - have you done a search? Also searching Google will give you loads of results.

You are absolutely right , I know there are a lots of result on google. but i want to learn from anybody who know clearly and that’s why i have come on forum .

Whatever thanks a lot

The only ones that will know clearly are Google employees.
The SitePoint forums can help you a lot with on-page optimization, i.e. valid and semantic mark-up, how to reduce page load time etc.
Sadly, most of the posts involving ways to “trick” the Search engines are quite useless if not damaging.
Posts here about off-page optimization even moreso.

Other than an actual Google employee replying to this thread, or someone doing a search for you and posting a link to the Google article they’ve found, this question is most unlikely to provide anything more that hasn’t already been said countless times.

Thanks for your kind reply