HTML is an abbreviation of the Hypertext Markup Language and CSS  is an abbreviation of Cascading Style Sheets. These both are core technologies for building Web pages. HTML provides the structure of the web page and CSS provides the styles and layout of web pages for various types of devices. HTML and CSS are the main sources for building Web applications and web pages along with graphics and scripting.

Hypertext Markup Language

Introduction to HTML (Hypertext Markup Language)

A language that is used to describe the structure of Web pages is called HTML. HTML provides means to authors are:

  • Publish online documents with text, headings, tables, lists, photos, videos and etc.
  • Fetch online information via hypertext links by clicking a button.
  • HTML also Designs forms for conducting transactions with remote services, for use in ordering products, searching for information, making reservations, etc.
  • It Includes video clips, spreadsheets, sound clips, and other applications directly in their documents and etc.

The authors describe the structure of pages using markup with HTML. The main elements of the HTML language are labels and pieces of content such as paragraphs, list tables, etc

What is XHTML?

XHTML stands for EXtensible HyperText Markup Language. It is HTML defined as an XML application. XHTML is supported by almost all types of browsers. It has the same elements as the HTML but the syntax is different. Because XHTML is an XML application so you can use other XML tools with it.

Why XHTML is Important?

All documents must be marked up correctly in XML. XHTML is an extension of HTML to work with other data formats such as XML. In HTML browsers ignore errors in webpages and display the website even if it has some errors in markup. XHTML is much strict in error handling as compared to HTML.

The Most Important Differences from HTML

  • <!DOCTYPE> is mandatory
  • The xmlns attribute in <html> is mandatory
  • <html>, <head>, <title>, and <body> are mandatory
  • Elements must always be properly nested
  • Elements must always be closed
  • Elements must always be in lowercase
  • Attribute names must always be in lowercase
  • Attribute values must always be quoted
  • Attribute minimization is forbidden