The Cell (from Latin cella, meaning "Small Room") is the basic Structural, Functional, and Biological unit of all known Living Organisms. A cell is the Smallest Unit of life that can replicate independently, and cells are often called the "Building Blocks of Life". The study of cells is called Cell Biology.
Cells make up the smallest level of a living organism such as yourself and other living things. The cellular level of an organism is where the metabolic processes occur that keep the organism alive. That is why the cell is called the fundamental unit of life.
The cell was first discovered and named by Robert Hooke in 1665.
Two-thirds of a cell is water, which means that two-thirds of your whole body is water. The rest is a mixture of molecules, mainly proteins, lipids and carbohydrates.