In biology, a cell ([sɛl], ”plural: cells”) is defined as the structural, functional, and biological unit of all organisms. It is an autonomous self-replicating unit that may exist as a functional independent unit of life (as in the case of a unicellular organism), or as a sub-unit in a multicellular organism (such as in plants and animals) that performs a particular function in tissues and organs.
Etymology: The term ”cell” came from Latin ”cella”, ”cellula”, meaning “a small room”.
information from Biology online
