What does a pre out do?

Thank you Newbee.I appreciate your help!

There are different kinds of pre outs:
One you use with jumper to the poweramp input(of the integrated amp) disconnects the poweramp section.
and another kind that will not disconnect the poweramp section and could be used together with different matching poweramp to biamp your speakers(again if such have two sets of binding posts each).

Thank you Marakanetz. Then would it be okay if you purchased an integrated amp with dual binding posts but the speakers are not bi-wire? Is this detremental or would it be okay. Thanks!

" Then would it be okay if you purchased an integrated amp with dual binding posts but the speakers are not bi-wire? Is this detremental or would it be okay "

It would be fine Ev314.