What are XML files used for?

Related questions

1. Does XML care about whitespace?
2. Does XML indentation matter?
3. What is DTD XML?
4. Where XML is used in applications?
5. Why do we use XML schema?
6. What is XML validation against XSD?
7. What is valid XML document?
8. Can XML tags have spaces?
9. What is XML schema used for?
10. What are the features of XML?

Tags

1. #common
2. #formats
3. #markup
4. #language
5. #similar
6. #intranets
7. #using
8. #elsewhere
9. #extensible
10. #share
11. #ascii
12. #standard
13. #extension
14. #world
15. #create
16. #format
17. #information