Abstract Language and APIs
- This specification defines an abstract language for describing documents and applications. It also provides APIs for interacting with in-memory representations of resources using this abstract language.
- The in-memory representation of these resources is known as "DOM HTML" or simply "the DOM."
Concrete Syntaxes
- There are various concrete syntaxes (specific rules for writing code) that can be used to transmit resources that use the abstract language.
- This section focuses on two concrete syntaxes defined in the specification: HTML syntax and XML syntax.
HTML Syntax
- The HTML syntax is the format recommended for most authors. It is compatible with most legacy web browsers.
- When a document is transmitted with the "text/html" MIME type, web browsers process it as an HTML document.
- The specification defines the latest HTML syntax, referred to simply as "HTML."
XML Syntax
- The XML syntax is an alternative option. When a document is transmitted with an XML MIME type (e.g., "application/xhtml+xml"), web browsers treat it as an XML document and parse it with an XML processor.
- It's important to note that the processing for XML and HTML differs. Even minor syntax errors in XML can prevent a document from rendering fully, whereas such errors are often ignored in the HTML syntax.
Former Term "XHTML"
- The XML syntax for HTML was formerly referred to as "XHTML." However, this specification no longer uses that term, and there are various reasons for this change. One reason is that the term "XHTML" is not used for the HTML syntaxes of MathML and SVG.
Differences between DOM, HTML, and XML Syntax:
- The DOM, HTML syntax, and XML syntax cannot always represent the same content.
- For example, namespaces cannot be represented using the HTML syntax, but they are supported in the DOM and XML syntax.
- Documents that use the "noscript" feature can be represented using the HTML syntax but cannot be represented with the DOM or in the XML syntax.
- Comments that contain the string "-->" can only be represented in the DOM and not in the HTML and XML syntaxes.
HTML and XML are both used to represent web content, they have distinct syntax and behavior, and they are suitable for different use cases. The Document Object Model (DOM) can be used to interact with both HTML and XML representations, but there are differences in what can be expressed using each syntax.
