What is XML?

XML is a markup language that provides a set of universal rules to describe data. It is the latest, powerful, platform independent and content dependent technology in the field of applications development. This article describes about the basic overview of XML, introduction to XML. Summary of the article:

• What is XML?
• History of XML
• Properties of XML
• Advantages of XML
• Disadvantages of XML
• Editors of XML

What is XML?
XML (Extensible Markup Language) is a markup language for describing hierarchical data. The term extensible is used to specify that the developer has significant freedom in the choice of markup elements. Which means, we can create customize tags with XML. It was originally designed for defining new document formats for the World Wide Web. XML is a text-based format that provides mechanisms for describing document structures using markup tags (<,>). It is derived from the SGML (Standard Generalized Markup Language) which is also text-based. In some case, XML was some similarities with HTML. Because, both they are derived from the SGML. That’s why someone may confuse. But both are not same. There exist some difference within XML and HTML. XML is not a replacement of HTML. It is language and machine independent.

XML can represent both tabular data (such as data from a relational database or spreadsheets file) and semi-structured data (such as a Web page or business document). XML can overcome popular existing data format CSV (comma separated value), RTF. Because, CSV either handle tabular data perfectly and semi-structured data poorly, or too specialized for semi-structured text documents.

History of XML
XML is invented in 1996.

Properties of XML
The XML has some properties or features that describes the characteristics of its. With this simple features we can gent basic overview and can understand the behavior of XML.  Some properties of XML are given bellow:

• It is a markup language and written in customize tags.
• Its’ primary purpose is to transport and store data.
• Developers can write customize tags.
• It is case sensitive.
• It is dynamic.
• It is neither a programming language not a presentation language. We can call it meta-language or a language that can be used to define other languages.
• It can preserves white space.
• It is strict and we need to close each tag that has been used.

Advantages of XML
XML provides lot of advantages. It is very much beneficial for the business. The benefits of XML are given bellow:

• It is very easy to read, write, and process.
• It follows an international standard (W3C standard).
• It is machine or device and language independent.
• It is a concurrently human and machine readable.
• It can represent the most general computer based data structures (lists, records, trees, etc).
• It supports customized tags.
• It is self descriptive.
• It can be deployed on any network.
• It supports Unicode.
• It provides validation facility.
• It is a schema driven language and for that reason huge programming knowledge is not required.
• It is very faster to access for any hardware or applications.
• It requires low space to store data.

Disadvantages of XML
XML has some disadvantage also which can impact our service. Before development we should consider its impact.  Some drawbacks of XML are given bellow:

• Lack of sufficient processing applications. To process XML documents extra applications are required. For example, there is no browser yet which can read XML. But anyone can read an html documents using any browser anywhere in the world.
• It is required to close each tag that has been used.
• XML syntax is redundant / large relative to binary representations of similar data. This redundant data may affect the performance, storage size, processing cost etc.
• XML syntax is verbose and sometimes this may be a problem for other human or applications.
• Its does not provides any strong data types like: integer, Boolean, date, and so on.

Editors of XML
There is lot of software or applications to create or edit XML documents. Some editors are plain text where all codes are visible to the designer. Some editors are graphical that hides the code in the background and present only the content to the user in more user friendly way. Graphical editors are more helpful for them, who are not fluent or new in XML syntax or code. A list of some XML editors is given bellow:

• Adobe FrameMaker
• jquery.xmleditor
• Microsoft Visual Studio
• XML Copy Editor
• XML Editor
• Liquid XML Studio
• oXygen XML Editor
• Notepad++
• XML Notepad

XML is very easy to learn and implement. It can be used to store, share or exchange data. We can convert different formats of data (html, CSV, relational data, etc) into XML easily. The successful uses of XML can improve our business.