what are cells?

There are 3 different cells and they are for plants, animals, and humans. Cells are like legos blocks because they are basic units of all living things. You can't look at cells with your eyes you have to look through a microscope. All cells are not the same they have there own structure. We never run out of cells because we get new ones from the existing cells. When we grow because our cells are making more and more and more cells.