Venting

I note alot of builders use fantastic vents in their builds. From my research I understand these are incredibly efficient extraction fans.
My question is if I install one do I need to install inlet vents to promote air flow? If so I would appreciate some guidance as to where and what to install?
Cheers
My question is if I install one do I need to install inlet vents to promote air flow? If so I would appreciate some guidance as to where and what to install?
Cheers