Google Authorship is a way to link content you create with a Google+ profile. Google provides a means to get started.
Google Authorship was primarily Google’s way to allow the authors of content to identify themselves for display purposes. You asserted it by making use of “markup,” code hidden from human view but within web pages. Google extended from this original idea to link it tightly with Google+, as a step to create a Google-controlled system of identifying authors and managing identities.
Those making use of Google Authorship were largely rewarded by having author names and images appear next to stories. That was the big draw, especially when Google suggested that stories with authorship display might draw more clicks