The cell theory was started by these two scientists named Theodor Schwann and Mattias Schleiden. The cell theory has been edited many times because other people have discovered things about cells that they didn't.
The cell theory explains what cells are, what they do, and how they make copies of each other.
I broke up the cell theory into two different parts. The first part has to do with living things. The second part has to do with making more cells.
Let's move on to the first part!