The phrase Web 2.0 was originally coined three or so years ago and, unless youhave been living on a far off planet or in a cave, no doubt you will have heard it.Perhaps you might have wondered what it is all about, or indeed, whether Web 2.0actually exists at all?It may seem a little strange to be asking whether something that people have beentalking about for three years exists or not, but the reason is that there is no easy-topin-down definition of what Web 2.0 actually is.Indeed, a measure of just how difficult it is to define Web 2.0 is that it is far easierto tie down what it is not!For example, it is not a particular type of website, although some sites (especiallyinternet marketing product sales pages produced over the last six months or so) arebecoming recognizable as Web 2.0 ‘style’ sites.More and more of these sites are moving away from strong, garish colors in salespage backgrounds and reverting to plain white or grey backgrounds.Whilst these are not Web 2.0 sites – there is no such ting – nevertheless, simplicityand plainness in site design is making a big comeback!The fact is that, if there is only one factor that can be said to represent Web 2.0, itcan be summed up as interactivity.