The human body is made up of uncountable small units, called cells. The cell is a very tiny form of the body. It is a functional and structural unit of the body that has the ability to run all the life process independently.
The cells of different body organs vary from each other, but the basic structure of them is similar. They are as tiny as it can not be possible to see them through our naked eyes i.e. without microscope. It can be seen only by keeping on a slide after staining. By staining, the different parts of the cells are changed in to various colors and start appearing clearly as different from each other. There are several parts found inside the structure of the cells, which are collectively called cell. The shape and structure of different cells vary from each other due to variations in their functions, but few special structural properties are found same in all of them.