A cell is the smallest unit capable of performing
all the activities of life (metabolize;
move; reproduce; etc.)
There are two main types of cells: prokaryotic
and eukaryotic.
prokaryotic cell: this type of cell lacks a membrane-enclosed nucleus
and membrane-enclosed organelles and is found only in
single-celled creatures.
Those creatures are collectively called prokaryotes.
eukaryotic cell:
this type of cell has a membrane-enclosed nucleus
and membrane-enclosed organelles
and is found in multi-celled organisms.
These creatures are collectively called eukaryotes and include fungi, animals,
and plants.