IPTV stands for internet protocol television. Traditionally, your TV stream reaches to your TV with cable or satellite receiver. IPTV is nothing different than others, just the way of channels reaching your TV is different. It’s with your internet connection.
There is no place without internet nowadays. Even in rural places, there is good chance you can have internet connection with your mobile phone. Almost last 10 years, all the TVs, set-top-boxes are able to connect WiFi.
When it comes down to availability, internet is most practical way rather than cable or satellite. That’s why IPTV channels are so much popular at these days.