In simple breakdown, SEO 1.0 includes website optimization, image optimization for Google Images, product feed optimization for eCommerce websites and SEO 2.0 includes Social Media Optimization, Article Submission and News Feeds Optimization, YouTube optimization and Local Business Optimization.
SEO 2.0 can be defined as the next generation of SEO. Formerly Google was giving major credit to inbound links to evaluate the rank of a website, but over the past few years a lot of algorithmic changes have been introduced. Inbound links still hold a powerful signal, but more factors have been introduced into the ranking signal like the ones mentioned above which help in deducing the rank of a website in Google.