The wireless adapter for your notebook pc or any other client device (end device) that you may be using. Here is a small selection to choose from.
From your core WiFi device extend or expand your wireless network coverage area by adding on an expander or two according to your needs. Today you have two frequency solutions available to you. 2.4Ghz solutions which can do many speeds and the new 5Ghz which can do higher speeds with less interference and competition.
From your internet service provider, you can replace the default router from your internet service provider. Get better bandwidth and clearer channels by having 2 frequencies to choose from the standard 2.4Ghz which even your bluetooth device rides on and the newer 5Ghz where there is less users on this frequency. It carries higher wireless bandwidths too.