XHTML (Extensible Hypertext Markup Language) is a markup language that is mostly used to create webpages. It is an XML-based version of HTML, created to improve upon the hypertext markup language, allowing for increased extensibility. XHTML is a World Wide Web Consortium (W3C) standard, and is used in combination with other web technologies such as Cascading Style Sheets (CSS), JavaScript and the Document Object Model (DOM).
The primary purpose for XHTML is to enable webpages to be written in a markup language that is platform-neutral, meaning that it is presented in the same way on all types of computers and browsers. The language also allows for more extensibility, enabling developers to create more complex webpages than they could with HTML. These features make XHTML important for developers designing interactive content for the Web.
XHTML is based on XML, which is a set of markup rules for formatting data. XML is an open standard, which means that software tools and languages developed to work with it can usually operate interchangeably with other tools and languages that are XML-based. This makes it easier for developers to create cross-platform applications.
The syntax of XHTML is largely based on that of HTML 4.0. This makes the language easier to learn; however, it is stricter than HTML 4.0. When coding in XHTML, all webpages must include a DOCTYPE declaration at the top and all tags must be properly closed. Also, all tags must be fully lower-case. In addition, attributes must use double quotation marks instead of single quotation marks.
XHTML is a powerful technology for structuring content on the Web, and is an important language for web developers to understand.
