What is XML
XML is a markup language designed by members of the World Wide Web Consortium (W3). The key features you often hear about XML are:
• XML stands for Extensible Markup Language.
• XML is a markup language much like HTML.
• Tags are not predefined in XML.
• XML describes data in a hierarchical format.
• A DTD (Document Type Definition) may formally describe the XML data.
An extensible markup language is not predefined by a fixed specification, or a standard, like HTML. Instead, only its characteristics are defined and its users must create their own tags and structure. However, when you work with an XML file, you are limited to the structure defined by its designer.
Although XML and HTML are both markup languages, their purposes are different. HTML is used to structure documents for display on the Web and is limited to a set of predefined tags. XML is used to structure data to be processed by an application that understands its structure. This includes the Web, but can also include any application designed to read XML data.
The XML structure may be defined by a Document Type Definition (DTD). The DTD strictly defines the tags you can use and their valid attributes. Manager Server XML does not have a formal DTD, but you are limited to the tags and attributes allowed by Creo Elements/Direct Manager Server.