XML stands for Extensible Markup Language, with the markup bit being the key. You can create content and mark it up with delimiting tags, making each word, phrase, or chunk into identifiable, sort able information. The files, or document instances, you create consist of elements (tags) and content, and the elements help the documents to be understood fairly well when read from printouts or even processed electronically. The more descriptive the elements, the more a document's parts can be identified. From the early days of markup to today, one advantage of tagging content is that if a computer system is lost, the data in print can still be understood from its tags.
Markup languages evolved from early, private company and government forms into Standard Generalized Markup Language (SGML), Hypertext Markup Language (HTML), and eventually into XML. SGML can seem complex, and HTML (which was really just an element set) was just not powerful enough to identify information. XML is designed as an easy-to-use and easy-to-extend markup language.
With XML, you can create your own elements, giving you the freedom to precisely represent your pieces of information. Rather than treating your documents as headings and paragraphs, you can identify each part within the document. For efficiency, you'll want to define a finite list of your elements and stick to them. You can define your elements in a Document Type Definition (DTD) or in a schema. As you start out and get used to XML, feel free to experiment with element names as you build practice files.
Some important features of XML:
- XML is a set of rules (you may also think of them as guidelines or conventions) for designing text formats that let you structure your data.
- XML uses the tags only to delimit pieces of data, and leaves the interpretation of the data completely to the application that reads it.
- A forgotten tag or an attribute without quotes makes an XML file unusable, while in HTML such practice is often explicitly allowed.
- XML Schemas help developers to precisely define the structures of their own XML-based formats.
- XML allows you to define a new document format by combining and reusing other formats.
- XML is license-free; you can build your own software around it without paying anybody anything.
You have to enter the line “” first to start writing XML code. Following shows a well-formed XML structure of some data. First you have to write it in notepad and Save As it with FirstData.xml file in your drive.
After that double click that file (FirstData.XML) and it’ll open in your default browser as shown bellow:
Labels: What's XML