Difference Between XML and HTML

Stands For
XML stands for  “Extensible Mark Up Language“. HTML stands for “HyperText Markup Language“.
XML is focuses on data stored and how its carried and described i.e. ‘XML Describes the Data‘. HTML is focuses on display and look of data i.e. ‘HTML Defines or Displays the Data‘.
Tag Criteria
In XML once a tag is opened, it must be closed. In HTML, its not necessary to close a tag.This is a paragraph.
Case Sensitive
XML is Case Sensitive i.e. Opening and closing tags must be in the same case. HTML is not Case Sensitive.
Define Tag In XML, there is no pre-defined tags, user have to define his own tags. In HTML,there is pre-defined tags and user have to use those tags.
Structure In XML, user can define his own tags as well as structure of document. in HTML, structure of HTML document as well as tags are pre-defined.
Extensible XML is an extensible so user can add own tags to extend the XML. HTML is markup language having its pre-defined tags and user can’t add own tags.

In XML value of attribute must always be quoted. In HTML it is not necessary to quote the values.
In XML, Elements must be nested properly. HTML is not so sensitive so it allows improper nesting.
Paired Tags There is only  Paired Tag in XML. There is Both types of tags, Paired tags and Singular Tags in HTML.
White space In XML, white space is preserved. In HTML, multiple white space is truncated to one single white space i.e. white space is not preserved.