The US, at least some of the Caribbean, Israel, and presumably Canada say 'cell.' 'Mobile' is used in Australia, NZ, UK, Ireland, Channel Islands, Anglophone Africa, Malta, and Europe (in their own languages and when speaking English). read more
Strictly speaking, a cell (cellular) phone is a mobile phone, but a mobile phone may not necessarily be a cell phone. "Cellular" refers to the network technology. A satellite phone is also mobile, but there are so few of them in use nowadays compared to cell phones that for most practical purposes (in urban areas for sure) they can be ignored. read more