Differenz between timeserver settings in w2000 and w2003

Can anyone please explain the differenz between the timeserver settings in w2k visa w2003. I know the time synchnronisation can be done by several registry settings. But i have although seen the method via Date and Time Properties (synchronize with an internet time server. What is the differenz between this methods???
Any help will be appreciated!

Thanks in advance!

Cheers
Aussie