What is Web 2.0? Web design 2.0? A question that many ask themselves, but to which no one can find a clear answer. A Google search returns more than 350 million results. It's not too bad for a term that no one can find an exact definition of. Tim O'Reilly's article "What Is Web 2.0", published in September 2005, is one of the basic articles that underpin Web 2.0 concepts.

Although it was not highlighted, there was a transition from web 1.0 to web 2.0, and the transition depended on a multitude of factors. When the web became commercial, in the early 1990s, there was an explosion of the Internet, the volume of information available on the Web taking on impressive proportions. At that time most pages were generally static. This period was later called web 1.0.

In the dotcom (.com) era, the services offered diversified, millions of news pages appeared, which were updated frequently. CMS - content management systems (content management systems) have become necessary. Anyone could create their own web page, either design it personally or with the help of free or open source CMS and there is the possibility of free hosting. This is known as the web1.5 period.

Web 2.0 is not the second version of a software or web technique. Web 2.0 designates (quite vaguely) new ways to consider and exploit the organizational possibilities of the web. According to them, the content and information on the web is no longer provided to visitors only by the media, governments and private companies, but also by private individuals, connected to each other through informal Internet-based networks, and who contribute and actively participate in the provision and spreading information around the globe through the web. Typical examples of this new aspect are the so-called wikis, weblogs or more simplified blogs, as well as portals and stock exchanges for images, music, movies / videos and software on the Internet, such as Flickr, YouTube and websites. for File sharing.

A description of Web 2.0 could be made by the following features:

• includes a very wide range of applications and services that use the Web as a unitary and organized communication platform;
• it is built on an architecture that encourages the active participation of users;
• allows easy interaction between users who have the same interests;
• an experience much closer to desktop applications, with intuitive, pleasant, programmable and, especially, transparent graphical interfaces;
• has the ability to connect various applications or services and to aggregate data from various sources - RSS, blogs;
• syndication - RSS and tag structures: the elimination of tree classifications and the application of labels so that one thing is no longer strictly descended from another but can be part of several categories;
• democratization of content and its distribution (content created by the user and freely distributed.

The techniques used by Web 2.0 are a combination of techniques that date back to the late 1990s, but which only nowadays (2007) are particularly widespread:

• Application Program Interfaces (APIs) for web services
• Asynchronous Javascript and XML (Ajax), as a descendant of XmlHttpRequest techniques
• Content syndication - subscription services, for example RSS - subscriptions to “Latest news”
• Integration of social software, such as blogs and wikis.

Web 2.0 is a web platform that is based on standards such as RSS, XML, APIs and utilities such as blogging, podcasting and other services. Web 2.0 is based on trust, a new generation of developers, the existence of Open Source, broadband and the desire to talk to people.