What is Cell ?
Cell is (noun) 1. a small room in a building such as a prison or monastery He was arrested in the centre of town and spent the night in the police cells. 2. the basic unit of a living creature or plant You can see the cancer cells under a microscope. 3. a small political group She formed part of a cell of activists. 4. a part of an electric battery (NOTE: Do not confuse with sell.)
source: Easier English, Student Dictionary Upper Intermediate Level