What is a DTD file in XML?

Related questions

1. What is XML schema validation?
2. Why do we need DTD?
3. Where do we use XML?
4. Why is DTD important?
5. What is XML document validation?
6. What is the difference between HTML and XML?
7. Why XSLT is important for XML?
8. What is DTD Why do we use it?
9. What is DTD explain its purpose What are the limitations of DTD?
10. What is use of DTD in XML?

Tags

1. #valid
2. #family
3. #inside
4. #external
5. #declarations
6. #definition
7. #building
8. #markup
9. #define
10. #reference
11. #declared
12. #document
13. #inline
14. #defines
15. #blocks
16. #language