Most things people now want to do on the internet can be done with only one piece of software, a web browser - such as Internet Explorer or Firefox. (Although you may have to download a few "extensions" to get it fully functional.)
Up until recently , if you wanted,for example, to watch a film online you probably had to download a piece of software to your computer. Each activity seemed to need its own tools. Now, all the software needed to do things is taken care of for you in one tool. That tool is the internet browser. It is the single application that allows us to access the film, music, animations, games and various communications of Web 2.0.
The effect of this has been to make use of the web much easier. Users do not have to worry about installing whole collections of separate programs. And they can be sure that any computer they go to will have the browser.
Not only that, the range of actions that browsers now allow you do perform is much greater. This means the browser is not longer just the "player" of films, games, messages etc. This increased interactivity allows much more opportunity for the user to participate in activities with others - to be a more active contributer to the world wide web..
Click here for a site that assembles lots of video demos illustrating how Web 2.0 applications work. Or see this Web2-style video celebrating the range of opportunities..