Best Wifi Extender and repeater for internet booster, best range wifi router, what is a wifi extender, wifi network extender, Netgear, Linksys, Asus extender. Wifi extenders are devices which are used to extend the range of coverage area of your wifi network for better connectivity in long distances or ranges. But let us know how do wifi extenders work, Wifi extenders rebroadcast the signals of your existing wifi.