One of the key differences between histology and cytology is that histology is a branch of biology that studies about tissues of animals and plants under the microscope while cytology is another branch of biology that studies cells under the microscope. Moreover, histological studies are broader, more detailed and more expensive than cytological studies.
Every living organism on earth constitutes of either a cell or a collection of cells except viruses. The cell is the smallest structural and functional unit of an organism. A tissue is a group of cells that perform a common function and has a similar origin. Different kinds of tissues work together and form an organ. An organ system is a collection of organs. Likewise, the animal or plant body comprises different levels of organizations with the increasing complexity of each level from cells to organ systems to organisms. Hence, unicellular organisms have simple structures while most multicellular organisms have very complex structures. Histology and cytology are two branches of biology that study the tissues of animals and plants and cells microscopically.
