Many WAPs that I have used can be put into 'client' mode, which means that a WAP is reconfigured so it knows account details, it logs on to a wireless LAN and listens and bridges stuff to and from their ethernet port. This is instead of the normal behaviour of a WAP where it creates and publishes a wireless LAN, but this is not itself visible as it does not have a 'name' on the wireless LAN. instead of an extender I did in fact in one place put one of these on to an ethernet cable straight into another normal WAP, so this connected two WLANs together, with different names. I don't know how 'extenders' work, as in my ignorance I am not aware of a standard. I hope they are doing store-and-forward and creating a new extension to the wireless LAN, rather than copying input signal, like a booster, at the physical level, which could cause interference I suspect, but I am not sure. There are big problems with the former approach in my opinion which I won't go into unless anyone wants the long version. But I have always stayed well away from extenders as I can see bad problems to my way of thinking, may be wrong, but I have an idea why afaik no buinesses use them. The best thing is to arrange multiple WAPs and have them putting out the same SSID. Look out for ones with good support for 'roaming' where stations move from one WAP to a different one if they move around. WAPs and client devices ('stations') vary a lot in how they handle this - modern software supports new-ish protocols for sane efficient handover / roaming and 'fast roaming' where handover is quick because the device arranges things with both new and old WAPs in that order and then switches. Also iirc there is a new protocol for devices getting info about which WAP is the good one to go to. A lot of rubbish WAPs do not support these newer features because they have skimped on the software. (My WAPs are too old for these good things.) It is important to check that the whole system does roam well. How clients decide when to move is anyone's guess, because they do not want the disruption but they need to balance the cost of that with staying on a weak WAP. It can be that clients will stick to a really weak WAP and not move, which is a nuisance. So check for modern standards support and the various new 802.11-<xx> specs in the details of WAPs and your own client devices and look for infor about how well certain clients work with certain WAPs if you can find any. I am all-Apple iPads so I found a doc jointly authored by Cisco about its WAPs and Apple cooperation and joint testing and development so that encouraged me to buy Cisco but that is another saga. On the contrary a guy wrote a lot about problems with Apple and Ubiquiti WAPs where Apple iPhone software broke after roaming, so luckily that warned me right off Ubiquiti which very cheap yet has impressive sounding design.