Web 2.0 involves many-to-many conversations on the internet instead of one-way publishing of content. It allows for collaboration and user-generated content through tools like blogs, wikis, tags, forums and RSS feeds. Dell got in trouble because they did not listen to customer feedback on blogs and forums, but later recovered by embracing Web 2.0 principles like opening communication channels and actively engaging with customers. The key aspects of Web 2.0 are communication, lightweight tools, and an organizational model that empowers employees and customers.