Hotspot for a mini-hotel - hardware, software, some clarifications?

Question

WiFi

Hello everyone, I have never come across this issue before, I googled a lot, but there are questions that haunt me.
There is a mini hotel, 3 floors, the area is not large.
There is a router, it is necessary to deploy a network with limited access.
You need to give access to a specific user on a coupon.
I read about UniFi, everything seems to fit, but they write that a DHCP server is needed - what is it and what does it eat with?
or maybe there are simple ways to install hotspot, preferably under windiws.
if possible, in a few words, the process itself (I don’t ask for instructions, but just to orient how it’s done)
thank you

Answer 1

An office is hired, it develops a technical specification, an estimate, you approve all this, pay.
Then smiling assemblers in overalls arrive, drill / gouge the walls, mount the equipment, pull the support network. Yes, a good wireless network requires a wired one.
Then a bearded guy in a sweater comes in, sets up this thing, and you get a ready-made working network.
This is just right for citizens to whom DHCP is something terrible and unclear (and Google is not at all clear what).
For the Internet to work "on coupons", you need to deploy either a complex using RADIUS for authorization (which is easier and more transparent for users), or a structure of a transparent proxy and a captive portal (users will cover you five floors for pop-up windows in the middle of surfing and put your Wi-Fi three stars on booking.How are you not on booking? Well lol, cho).