Sigfox allows low consumption, long range (about 15 Km) and low data rate data communication. It is not necessary to have a SIM card to transmit data. There are 7 standards on the network, with frequency modulation, depending on the geographical area.
The GSM network is the one used by our phones for communication, with a lower range and higher consumption. It is necessary to have a SIM card compatible with the country of use.