The Google Rules for Webmasters (called Google Webmaster Guidelines) are there:https://support.google.com/webmasters/answer/35769?hl=en
Blackhat SEO can be technique for bulk, automatic building of backlinks to an website (made by marketing tools like Xrumer, Scrapebox, Senuke). This is forbidden by Google in their Webmaster Guidelines, "Link schemes" page:https://support.google.com/webmasters/answer/66356?hl=enBlackhat
is dangerous and can lead in Google penalizing a website which means low or no visitorsWhitehat
is the onpage and offpage optimization which follows above mentioned Google guidelines.