Mark-up Language Differences

Hi! Sorry if I post my question about mark-up language here. I'm just confuse where should I properly post my query so I decided to post here. What is the difference between xml and xhtml?

XML = is a standard for data transformation between computers , it holds only data with a specific formats (instead of database or binary files)

HTML= is mark up for web pages that is control the layout and the presentation of your web page, your browser is the one who understands the meaning of each HTML tag.