Web 2.0 is a collection of technologies that make Internet websites more interactive and encourages customers to produce content and make comments. They also help web software behave more like desktop software. For example:

• Ajax is a technology that reduces the communications delay while web-based applications send data to and from the server. It opens up opportunities for web-based applications to behave more like desktop software. An example of an Ajax application is Google Maps.
• Wikipedia is a website that allows anyone to contribute content.
• Social bookmarking sites like Digg and Del.ic.ious allow people to vote for content on the Internet that is interesting and appealing.