Phantom power is a mixer/interface supplied voltage that runs up the mic cable to power some microphones that are made to use phantom power - kind of like an active pickup or mini preamp right in the mic.
Preamps are little amplifiers in the mixer that raise the signal level before they into the mixing channel.
A track in a mixer could very well use both, I have never seen Phantom Power without a preamp also but i have also never seen a badger.
If you are going to be doing vocal recordings and want great sound, get an interface that has phantom power and preamps. Most do - and you can always buy a stand alone preamp unit if your mixer doesnt have them or you dont like its sound - gets pricey though - but of course this is recording gear so "gets pricey" kinda goes without saying. Not that there are not inexpensive alternatives for everything