Download the PDF > XML essentials eXtensible Markup Language Tag based syntax, very much like HTML but not a replacement for it Recommendation of W3C 1998 Base for several web technologies such as XHTML, AJAX, RSS/ATOM, Web services Used for structure and describe data Enables communicate between different systems and services Hosts different related technologies such as XPath, XSLT, XQuey, XPointer/ XLink Advantages Separates presentation layer XML files can be read by many applications such as Java, .Net, PHP, JavaScript and etc. Can be used with Server side and Client side Disadvantages Not suitable for large data files (like 1GB of data) Not suitable for image like data JSON may be better solution for some cases other than XML Basics of XML Elements Naming Can only start with hyphen (_) or with letter Rules of XML Syntax Must have single root tag Must well formed Must have end tags Attributes must inside quotes XML Namespaces Prevents fro