Difference between XML and HTML

1) XML is not a replacement for HTML.
2) XML and HTML were designed with different goals.
3) XML was designed to describe data and to focus on what data is.
4) HTML was designed to display data and to focus on how data looks.
5) HTML is about displaying information, XML is about describing information

XML

User definable tags
Content driven
End tags required for well formed documents
Quotes required around attributes values
Slash required in empty tags

HTML
Defined set of tags designed for web display
Format driven
End tags not required
Quotes not required
Slash not required