The term cell is used in various fields: in biology and in high-tech.
A cell is the basic unit of all organisms (except viruses). The cell membrane separates it from the exterior in the case of single-cell organisms, and from other cells in the case of multi-cellular organisms, making the cell an entity.
The cell contains the genome (DNA), organelles (such as the endoplasmic reticulum, chloroplasts etc.) and many more or less organised biological molecules.
In ATM (asynchronous transfer mode), a cell is a standardised mini-packet containing 48 bytes of data and 5 bytes of address. ATM switches
In radio-communications, an area is divided into a network of cells which are assigned a set of frequencies that are non-reusable in adjacent cells.
In biology, cells (with the nucleus shown in pink) can assemble to form multicellular organisms. © BlueRidgeKitties, Flickr, CC