What is the difference between html and xhtml

Generaly talking, there is no difference. Both are tags related markup language and using similar tags to display web pages.

There is yet a "big" difference between the 2 but at programmer level.

html allow a large set of "mistakes" without displaying errors while xhtml is very strict.

In short words, xhtml is the very clean html, programing point of view.

Assuming you know at least basics about html, here are 2-3 examples:

in html you may have some tags unclosed, such as< p>. In khtml is error.
in html you can use capital letters, such as< BODY>, in xhtml you MUST use only lowercase
in html you mai mix closing tags - for example< b>< i> ... , in xhtml that is error.

and so on ..

hi 1anurag1
html means hyper text markup language and xhtml means extended hyper text markup language.in html we only use predefined tags to creating webpages.in xhtml we can create own tags for creating webpages.

There are many differences between HTML and XHTML indeed.

The most important difference between the html and xhtml is that HyperText Markup Language, or HTML, is an application of SGML and allows an author to omit certain tags and use attribute minimization. The Extensible HyperText Markup Language, or XHTML, is an application of XML. It doesn’t permit the omission of any tags or the use of attribute minimization.

XHTML is not very different from the HTML 4.01 standard.

So, bringing your code up to the 4.01 standard is a good start.

Our complete HTML 4.01 reference can help you with that.

In addition, you should start NOW to write your HTML code in lowercase letters, and NEVER skip closing tags .
The Most Important Differences:

XHTML elements must be properly nested
XHTML elements must always be closed
XHTML elements must be in lowercase
XHTML documents must have one root element