Cells are tiny and they make up every living organisms in the earth. Cells are different to tissues because tissues are MADE of cells and they have lots of similar tiny cells that make them what they are. Both of these are different to organs b/c organs are made of tissues. therefore they are made of cells. Finally, organ systems are differ b/c they are made up of organs and we have organ system that run our bodies and without these we wouldnt be able to survive.