|To clear that up for you....the booster, is often a form of antenna with an amplifier that attaches to router wifi antenna spot. It's job is to amplify or boost the normal signal and blast it further.|
The Extender, is basically a fancy amplifying repeater that is placed in range of another router, grabs the signal from the original router and extends the signal again from the new router/extender. This option gives you some flexibility in placement to reach selected areas, whereas the booster is usually a rectangular shaped box, close to the router it attaches and must blast it to all areas you need, sometimes they blast sufficiently and sometimes not, depends on the strength of the unit.
To err is human but to really screw things up, you need a computer!