XHTML, short for Extensible Hypertext Markup Language, is a markup language that is a stricter and cleaner version of HTML (Hypertext Markup Language). It is based on the XML (eXtensible Markup Language) format, which allows the creation of valid and well-formed web documents that are readable both by humans and machines.
XHTML combines the best practices and syntax rules of HTML with the rigidity and meticulousness of XML, leading to a more structured, standardized, and modular approach in web document creation. It provides a precise and accurate definition of elements, attributes, and their relationships.
The main objective of XHTML is to ensure compatibility across different platforms and display devices, including web browsers. It embraces the separation of content (HTML) and presentation (CSS), enabling developers to focus on distinct aspects of web development. This separation also fosters easier maintenance, updates, and redesigns of websites.
XHTML strictly adheres to the rules of well-formedness, requiring every element to be properly nested, closed, and attribute values wrapped in quotes. XHTML documents are typically written in lowercase and attribute names are in lowercase with hyphen separators.
Despite being stricter, XHTML offers backward compatibility with HTML, allowing older HTML documents to be easily converted or gradually migrated to the XHTML format. This facilitates a smooth transition from the traditional HTML to the more structured and standardized XHTML markup language.
