what is the differance between NEDS ceftified and compliance

NEBS is the Network Equipment and Building Standards, a Family of
Requirements published (for way too much money :-) by Telcordia, the
Standards Body Formerly Known As Bellcore.

Telcordia operates a certification laboratory wherein, for even *more*
money, they will test equipment to make certain it *passes* the NEBS
tests.  That's "certified".  On the other hand, vendors can buy the
standards, and design their products to meet those standards, but not
pay the money to have them tested by Telcordia.

That's "compliant".  It's less expensive, but you're trusting the
vendor.