Does the parabolic wifi booster increse coverage in all areas?

I am interested in building one of those parabloic wifi boosters that are shown on this site, but if i make this will it decrease my wifi in some areas and increase it in others?

NachoMahma7 years ago
. Yes. A parabolic is directional.
fwjs287 years ago
uhh, decrease, i don't thik so...