A cell is the basic structural and functional unit of all living organisms, while a molecule is a group of atoms bonded together. Cells are made up of molecules, which are the building blocks of cells and all living things. Cells can be simple, like bacteria, or complex, like human cells, while molecules can be simple, like water (H2O), or complex, like DNA. Cells can perform various functions, such as growth, reproduction, and metabolism, while molecules can participate in chemical reactions and form the basis of biological processes. In summary, cells are the structural and functional units of living organisms, while molecules are the building blocks of cells and all living things.