Technically, WiFi is a layer 2 local area radio technology. You can connect 2 devices over a WiFi network using 802.11x but that alone will not get you to the Internet. You have to have a second, separate connection via a modem, gateway or router into either the wired/optical network (cable, Uverse or DSL), or cellular RAN technology (e.g. ATT, Verizon, etc., LTE) to get to the Internet. McDonalds, Starbucks, hotspots etc. are layer 2, 802.11x radio then into the wired network, and the radio portion is often open, unsecured and can be snooped. OTOH, most carrier WiFi hotspots that you can buy combine the layer 2 wireless Ethernet with LTE RAN access as the second hop. That is why the carrier hotspot you buy have a SIM card and telephone number. The first hop may be unsecured (although today, most are default encrypted with WEP, WPA, etc. and there is a second unsecured channel for guest access), and the second hop into the cellular network is encrypted.