Roaming - definition

Roaming is one of the important terms discussed in telecommunication. When a mobile phone is operating outside of the home network coverage or using a different carrier then it is called roaming. For example, if you’re using a Verizon as a home carrier and you’re out of Verizon’s coverage but still using the network or connected to the internet then you’re on a roaming facility. It can use different supporting carriers to keep the network connectivity. In roaming the device's IP address remains unchanged.

Point to be noted, while on roaming, then the tariffs are comparatively much higher than the home carrier.