Web 2.0 pertains to websites that emphasize user-generated content, usability, and interoperability for end users all over the world.
The participative social web is another name for Web 2.0. It does not refer to a change in a technical definition, but rather to a change in the way Web pages are built and used. The transition is advantageous, although it does not appear to be the case when the changes occur.
Web 2.0 allows users to interact and collaborate with one another in a social media dialogue as creators of user-generated content in a virtual community.
AJAX and JavaScript frameworks are among the web browser technologies that are employed in Web 2.0 development.

Where as, Web 3.0 is a catch-all term that encompasses a variety of web usage and interaction evolutions. Data isn't owned in this case; instead, it's shared, with multiple views for the same web / data being displayed by different services.
It involves the embedding intelligence throughout the web and deploying robots to make decisions on the user's behalf. It is concerned with the establishing a uniform standard for websites to express content so that any computer program can comprehend the semantic meaning given by the web page.

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