what is the difference between <s,<mx,<fx tabs

What is the difference between<s,><fx,><mx tags. when do i use each.

Thanks
Anil>

That depends on what componentss you've defined in those namespaces.

These are new tags intorduced in Flex version-4.

<s--stands for spark componets that are introduced newly in Flex4.
<mx--mxml components that are used in Flex 3 and also supported in Flex4
<fx--Declaration tags

As Paul suggested we have to use proper namespaces in order to use them.

For more information look for Adobe documentation site.