It sounds like a personal hotspot that uses cell towers to connect to the internet. In other words, your wifi device connects to the pocket wifi and in turn that connects to the cell network. I had a personal hotspot that my wife used in our car to connect to the internet while on the road. We eventually gave it up because we didn't use it enough to justify the monthly cost. I once saw a family about to use one at Mullet beach because they thought that it would be free(they had the little wifi icon on their phone)until I told them that they would be charged for roaming because it really uses cell time. They were hesitant to believe me until a woman sitting next to them confirmed what I said.