XML Introduction

XML Introduction:-
 
Most of you could have heard or seen something called “Web Services”. What is this web service? In Web Services Glossary of W3C Working Group Note 11 February 2004, it is defined as:

            A Web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards. [http://www.w3.org/TR/2004/NOTE-ws-gloss-20040211/#webservice]

It is clearly seen that it says about machine-to-machine interaction over network. So there is a need for a common format or language that could be used and understood by these machines. Hence there arose a new language called XML [Extensible Markup Language]. It’s a markup language which is both machine readable and human readable. It is a version of SGML [Standard Generalized Markup Language] which provides standardization for markup languages. XML is mainly used to describe the data. It similar to html but they are entirely different (Discussed later).  XML could be used with lots of platforms like C#, VC++, Java, Python, PHP etc. It also forms the basis of various technologies like SOAP, semantic web, etc. XML has tags which is used to describe the data. These tags are not predefined. User or developer has to define the tags and hence it is very flexible. XML is a plain text and hence it could be edited easily. It is used for storing small amount of data and to tell what kind data.

 As mentioned earlier there is a great difference between XML and HTML. XML is used to describe data or tells what the data is about. But, HTML is used to display the data or used to visualize the data. Thus XML is about describing and storing information while HTML is about displaying information. XML tags are user-defined while HTML tags are predefined.

Example: Consider you want to describe the details of a book called “Around the world in 80 days” in XML.

Example:-

<?xml version="1.0" encoding="UTF-8"?>

<Book_1>

            <Name>Around the World in 80 Days</Name>

            <Author>Jules Verne</Author>

            <ISBN>978-0-8129-6856-9</ISBN>     

</Book_1>

That’s all folks for now!

Advertisement