Web 2.0 is the term applied to forms of interactive websites where content can be dynamically created and where applications can be run entirely through browsers.
Many of the site achieving this employ browser technologies such as Flash and AJAX.
The new sites considered Web 2.0 sites are most social-networking sites, video sharing sites, blogs, wikis, hosted services, and web applications.
Here is a great video breaking down Web 2.0.
1f0a8d47-3f52-4c42-8dbe-729c2331cb45|0|.0
AJAX is an acronym for Asynchronous JavaScript and XML. It isn’t a
programming language in itself , but is comprised of other existing technologies.
These technologies being HTML, Cascading Style Sheets (CSS), JavaScript,
the Document Object Model (DOM), XML , XSLT , and the XMLHttpRequest object.
With all of these components combined the creation of dynamic user interfaces on websites and web applications much easier. Since AJAX is asynchronous you can instantly update selected portions of the web pages rather than having to refresh the page each time a change has occurred. It can do this because rather than having a HTTP request that just goes back and forth from the website to the server, the AJAX engine becomes an intermediary between the two. The AJAX engine passes all server requests through JavaScript with the XMLHttpRequest object, while the AJAX engine itself handles all other request that don’t need to access the server.
To break down the process HTML and CSS are still used to format and stylize the webpage, while JavaScript is used to access the Document Object Model which causes the displayed information to become more dynamic and interactive. The browser and server interaction is passed through the XMLHttpRequest object. And the data sent
back to the browser is commonly formatted with XML.
43a91136-8784-4a49-9429-75a58ef74bfb|0|.0