What is the difference between XML and HTML?

What is the difference between XML and HTML?

XML is no way clashes with HTML, since they are for two different purposes.

HTML	XML
HTML is for displaying purpose.	whereas  XML is for data representation.
HTML is used to mark up text so it can be displayed to users.	XML is used to mark up data so it can be processed by computers.
HTML describes both structure (e.g. <p>, <h2>, <em>) and appearance (e.g. <br>, <font>, <i>)	XML describes only content, or “meaning”
HTML uses a fixed, unchangeable set of tags	In XML, you make up your own tags