Markup Languages: More Than HTML5

Since markup is the essence of web documents, it provides the largest place for standardization efforts. The popularity of HTML has not decreased since the birth of the Web. Becoming familiar with the versions and variants of that language and understanding the differences between HTML and XHTML are crucial for understanding the techniques for changing the document type. The general structure of all web documents follows the same logic. The latest core version and by far the most popular markup language of the World Wide Web, HTML5, introduced new structuring elements as well as multimedia element annotations that can be used to create rather sophisticated document structures. By examining well-structured document examples, you will be able to build correct document structures on your own. To achieve well-structuredness, the block-line and inline-level elements should be differentiated, which is also important in understanding how to embed elements into each other (element nesting). You should also know how to use Formal Public Identifiers and Document Type Definitions for creating standard-compliant documents. The strict rules of XML declarations are vital for XHTML authoring. HTML5 can be used to create HTML or XHTML documents (HTML5 or XHTML5, respectively), and documents that can be interpreted either as HTML or XHTML (polyglot markup).