Maestro C and internet

I'm a little confused by what I've been reading up here. The Flex description suggests you can use the unit around the house. If you can use the unit around the house then it must use WiFi, correct? Yet I read a lengthy stream up here talking about needing a travel router and a small cat cable to hook the Maestro to the travel router that would then be connected by wifi to the internet.

I'm seeking clarification, can I use the unit wirelessly around the house and if so, why can't I use it on a foreign wifi network i.e. a hotel wifi?????

Thanks

Peter