Attribute	XHTML	XML
Definition	XHTML is a markup language that is based on XML and is used for creating web pages.	XML is a markup language that is used for storing and transporting data.
Tags	XHTML has predefined tags for structuring web content, such as , , , etc.	XML does not have predefined tags. Users can define their own tags based on their specific needs.
Strictness	XHTML has stricter syntax rules and requires well-formed markup.	XML has flexible syntax rules and allows users to define their own rules.
Compatibility	XHTML is compatible with older HTML versions and can be easily converted from HTML to XHTML.	XML is compatible with various platforms and can be used with different programming languages.
Rendering	XHTML is designed for rendering web pages in web browsers.	XML is not designed for rendering. It focuses on data storage and transport.
Usage	XHTML is primarily used for creating web pages and web applications.	XML is used for data storage, data exchange, configuration files, and more.

Introduction

Extensible Markup Language (XML) and eXtensible HyperText Markup Language (XHTML) are both widely used in web development and data representation. While they share some similarities, they also have distinct attributes that set them apart. In this article, we will explore the key differences and similarities between XHTML and XML, highlighting their respective strengths and use cases.

What is XML?

XML is a markup language designed to store and transport data. It provides a flexible and self-descriptive format for representing structured information. XML documents consist of elements, attributes, and text content. Elements are enclosed within start and end tags, forming a hierarchical structure. Attributes provide additional information about elements, while text content represents the actual data.

One of the key advantages of XML is its platform and application independence. It can be used across different programming languages and systems, making it highly versatile. XML also supports internationalization and localization, allowing for the representation of data in various languages and character encodings.

XML documents are typically used for data exchange, configuration files, and representing complex structures such as hierarchical data, documents, or records. It is widely adopted in industries such as finance, healthcare, and e-commerce due to its flexibility and extensibility.

What is XHTML?

XHTML is a stricter and more standardized version of HTML, which is based on XML. It combines the syntax and rules of XML with the familiar tags and elements of HTML. XHTML documents must adhere to XML syntax rules, making them well-formed and compatible with XML parsers.

One of the main advantages of XHTML is its compatibility with XML tools and technologies. Since XHTML is an XML application, it can be processed and manipulated using XML parsers, XSLT transformations, and other XML-related tools. This makes it easier to integrate XHTML with existing XML-based systems and workflows.

XHTML also promotes cleaner and more consistent coding practices compared to HTML. It enforces strict rules for element nesting, attribute quoting, and case sensitivity, which helps developers write more maintainable and error-free code. Additionally, XHTML documents are more accessible and device-independent, as they can be rendered by a wide range of devices, including desktop browsers, mobile devices, and assistive technologies.

Key Similarities

Despite their differences, XHTML and XML share some fundamental similarities:

• Markup Language: Both XHTML and XML are markup languages used to structure and describe data.
• Extensibility: Both XHTML and XML allow for the creation of custom elements and attributes, enabling the representation of specific data structures.
• Self-Descriptive: Both XHTML and XML are self-descriptive, meaning that the structure and meaning of the data can be understood without external documentation.
• Compatibility: XML parsers and tools can process both XHTML and XML documents, allowing for interoperability between the two formats.

Differences in Syntax

While both XHTML and XML share a similar hierarchical structure, they differ in their syntax requirements:

• Tag Naming: In XHTML, tag names must be written in lowercase and follow the rules of HTML. XML, on the other hand, allows for case-sensitive tag names.
• Attribute Quoting: XHTML requires attribute values to be enclosed in double quotes, while XML allows for both double and single quotes.
• Empty Elements: In XHTML, empty elements must be closed with a trailing slash, such as <br />. XML, however, allows for empty elements to be self-closed without the trailing slash, like <br>.
• Character Entity References: XHTML supports predefined character entity references, such as &lt; for the less-than symbol (<), while XML requires the use of numeric character references, such as &#60;.

Use Cases

XML and XHTML are used in different contexts and serve distinct purposes:

• XML Use Cases: XML is commonly used for data exchange between systems, configuration files, and representing complex data structures. It is widely adopted in industries such as finance, healthcare, and e-commerce.
• XHTML Use Cases: XHTML is primarily used for web development, where strict adherence to standards and compatibility with XML tools are required. It is used to create accessible and device-independent web pages that can be rendered by various devices.

Conclusion

In summary, XML and XHTML are both powerful markup languages with their own unique attributes. XML provides a flexible and platform-independent format for storing and exchanging data, while XHTML combines the syntax of XML with the familiar elements of HTML, promoting cleaner coding practices and compatibility with XML tools.

Understanding the differences and similarities between XHTML and XML is crucial for developers and designers working with structured data and web development. By leveraging the strengths of each format, they can create robust and interoperable solutions that meet the specific requirements of their projects.