Google Adwords is were you pay to advertise your website Google Adsense is were you get paid to show ads on your website
Google Adwords and Google Adsense are two phases of a coin, both of these services are owned by Google, both of these services are used for generating online income from web based resources. Google Adwords is used to acquire a lead, sale or business proposal by marketing and sales professional. On the other hand Google Adsense is used by webmasters and online content creators for making some money from there contents by displaying relevant ads along with there contents.
You pay and advertise your site. Here you use Google Adwords. Google puts advertisements and pays for it to you. Here you use Google Adsense.
In google Adwords, You are the advertiser In google Adsense, You are the one being paid by the advertisers.
Google Adwords is where you advertise and get paid by Google Gogole Adsense is where Gogole display ads and you get paid for it