The WiFi world is full of terminology that can seem confusing and difficult to understand what is what. This is in part because many novices have come to use words like booster, extender, repeater interchangeably while they are techinically different things. 

For example, a USB Adapter is not a booster - it is techniclly a very sensitive receiver. An access point is a repeater and also a receiver as well as a transmitter depending on how you configure it. A router only transmits your hotspot's signal and cannot receive and repeat on it's own. 

Here's a quick video on what antennas do and check back soon for more videos on WiFi terminology.