It is the next step in the evolution of the internet. 0 is the first document type in the XHTML family. XHTML is almost introduction to xhtml pdf to HTML 4. 01 with only few differences.
This is a cleaner and stricter version of HTML 4. If you already know HTML, then you need to give little attention to learn this latest version of HTML.
By migrating to XHTML today, web developers can enter the XML world with all of its benefits, while still remaining confident in the backward and future compatibility of the content. Developers who migrate their content to XHTML 1. XHTML documents are XML conforming as they are readily viewed, edited, and validated with standard XML tools.