Web 2.0 & Ajax Basics

This document discusses Web 2.0 and AJAX technologies. It defines Web 2.0 as focusing on user participation, sharing, and collaboration using technologies like blogs, wikis, and AJAX. AJAX is defined as using asynchronous JavaScript and XML to update parts of a web page asynchronously without reloading the entire page. Examples of popular AJAX applications are given like Gmail and Google Maps. The technologies used in AJAX like XMLHttpRequest are discussed along with the asynchronous request-response process and browser support. Security considerations for both server-side and client-side AJAX applications are also covered.