Difference between HTML and XML:
1) HTML is presentation language where as XML is not either a programing language or a presentation language. It is used to transfer data between applications and databases.
2) HTML is not case-sensitive where as XML is case-sensitive.
3) HTML tags are predefined while XML tags are not predefined.
4) In XML we can define our own tags as it is not possible in HTML.
5) In XML it is mandatory to close each and every tag where as in HTML it is not required.
6) XML describes the data where as HTML only defines the data.