Extensible Mark Up Language

Extensible Markup Language(XML): Introduction - Creating XML Documents - XML style Sheet – Hyperlinks inXML Document Object Model - XML Query Language

1. Introduction to XML

XML (Extensible Markup Language) is a markup language that is mainly used to store and share structured data between different systems. It focuses on describing what the data is, rather than how it should be displayed. It was developed by the W3C to provide a universal, platform- independent format for data exchange.

Why XML?

• HTML displays data → XML describes data.

• Data stored in XML is readable by both humans and machines.

• XML is used in web services, configuration files, databases, IoT devices, APIs,

messaging systems etc.

Key Characteristics

• Extensible: Users can create their own tags.

• Structured: Data is stored in a hierarchical (tree-like) format.

• Platform Independent: Works on any OS and programming language.

• Supports Unicode: Suitable for multi-language storage.

• Self-descriptive: Tags explain the meaning of data.

Advantages

• Ideal for data interchange between different applications.

• Can be easily validated using DTD or XML Schema.

• Enhances reuse of data across web and non-web systems.

Where XML is commonly used

Area Use

Web Services SOAP messaging

Databases Data storage and transport

Configuration Files .config, .manifest, .xaml

Scientific/Business Data Standard data reporting