XML: eXtensible Markup Language

XML is also a mark-up language similar to HTML but is designed to transport and store data.

UNIT IV CONTENTS

XML Introduction, XML DTD, XML Schema, Parsing XML, XML Path, XML Tranformations.

XML Introduction

  • XML stands for eXtensible Markup Language.
  • It is also a markup language like HTML. The major difference is that XML is designed to carry and store data where as HTML which is intended to display data.
  • The following are the differences between HTML and XML.
    HTMLXML
    HTML stands for Hyper Text Mark-up Language. XML stands for eXtensible Mark-up Language.
    HTML tags are pre-defined. You create your own tags in XML.
    HTML is designed to display data. XML is designed to carry & store data.
    Focus is on how data looks. Focus is on what data is.
    HTML is case insensitive. XML is case-sensitive.
    HTML is not STRICT. For example, no warning will be given if the close tag is skipped in HTML. XML is STRICT. All tags must be closed and missing any close tag is not allowed.
    White spaces are not preserved in HTML. White spaces are preserved in XML.
  • The basic syntax of an XML code is as follows:
    <STUDENT>
    <SNAME> Ratna Raju </SNAME>
    <ROLL> 10PA1A1242 </ROLL>
    <CLASS> III IT </CLASS>
    </STUDENT>
  • The XML can be used to create self-explinatory code as above.
  • XML does not do anything. It is just information wrapped in tags. This in turn is used to different programs (parsers) to send, receive or display it.
  • XML does not have any pre-defined tags. HTML tags such as <H1>, <HTML>, <TABLE> are not recognised by XML.
  • XML is not a replacement to HTML. Its a complement to HTML.
  • XML is a W3C recommendation and is the most commonly used tool for data transmissions between all sorts of applications.