Apache Xerces - XML Overview

What is XML?

XML is a simple text-based language which was designed to store and transport data in plain text format. It stands for Extensible Markup Language. Following are some of the salient features of XML.

• XML is a markup language.

• XML is a tag based language like HTML.

• XML tags are not predefined like HTML.

• You can define your own tags which is why it is called extensible language.

• XML tags are designed to be self-descriptive.

• XML is a W3C Recommendation for data storage and transport.

Example

<?xml version = "1.0"?>
<Class>
   <Name>First</Name>
   <Sections>
      
      <Section>
         <Name>A</Name>
         <Students>
            <Student>Rohan</Student>
            <Student>Mohan</Student>
            <Student>Sohan</Student>
            <Student>Lalit</Student>
            <Student>Vinay</Student>
         </Students>
      </Section>
      
      <Section>
         <Name>B</Name>
         <Students>
            <Student>Robert</Student>
            <Student>Julie</Student>
            <Student>Kalie</Student>
            <Student>Michael</Student>				
         </Students>
      </Section>
      
   </Sections>
</Class>

Advantages

Following are the advantages provided by XML −

• Technology agnostic − Being plain text, XML is technology independent. It can be used by any technology for data storage and transmission purpose.

• Human readable − XML uses simple text format. It is human readable and understandable.

• Extensible − In XML, custom tags can be created and used very easily.

• Allow Validation − Using XSD, DTD and XML structure can be validated easily.

Disadvantages

Following are the disadvantages of XML usage −

• Redundant Syntax − Normally XML file contains numerous repetitive terms.

• Verbose − Being a verbose language, XML file size increases the transmission and storage costs.