XML

eXtensible Markup Language (XML) is a widely used text markup language that is used to exchange structured data between various web applications. XML allows publishers to tag specific pieces of data, in similar syntax to HTML tags, to allow for easier processing of data. XML is often used in the context of an "XML feed", which is a group of items with that are tagged using the standard XML structure. An XML feed usually contains a number of items which contain their own set of values for each. For instance, an XML feed showing book orders may contain a list of customers (items) that would each contain the tags , and , in where all tags would have values relating to the specific customer. The application using this feed would know how to process the data in a simple manner as each piece of information has been tagged descriptively.