What is Web 2.0?
Web 2.0 is frequently used SEO offpage submission in terms of developing the extra external webpage including content which clearly point your official website.
It also helps in Search Engine Optimization through content syndications.
In other words, Web 2.0 is the online technique that is used to share the content on different platforms like Tumblr, Weebly, WordPress, Blogger.
When you are referring a Web 2.0 for backlinking means you are creating the content for the domain. It is very beneficial to gain more traffic for your domain.
Similarly, you can say it’s a platform to create a micro-website and help to boost your domain and ranking of keywords in search engine. It is quite similar to article submission.