A cell is a single unit or compartment, enclosed by a border or wall. As a term, cell has become a general-purpose metaphor for building blocks which serve to compose larger structures.

In science:

• Cell (biology), the smallest metabolically-functional unit of life; see List of topics in cell biology
• Cell (journal), a bi-monthly peer-reviewed scientific journal related to biology
• Electrochemical cell, a setup used for creating an electromotive force
• Cell (geometry), in Euclidean geometry, refers to a 3-dimensional facet in a polytope
• A cellular automaton is a mathematical model consisting of a grid of cells whose states are changed according to a set of rules
• A part of the wing of an insect, surrounded by veins. Often important in determination of species

In technology:

• Cell microprocessor, a microprocessor developed jointly by IBM, Toshiba, and Sony
• A cellular architecture is a type of computer architecture
• Memory cell, in computer science, a building block of computer memory
• Cell (spreadsheet), a component part of a spreadsheet defined by its row & column (eg. "A1")
• Cell, (radio communications), a small geographic area of radio coverage served by a cell site (radio tower and equipment).
• Cell phone, a mobile phone for communicating through a cell site.