Here's a breakdown:

* Molecule: A molecule is a group of two or more atoms held together by chemical bonds. They are extremely small, on the order of nanometers (billionths of a meter).

* Cell: A cell is the basic unit of life. It is a complex structure containing many different molecules, organelles, and other components. Cells are much larger than molecules, typically ranging from a few micrometers to hundreds of micrometers in size (a micrometer is a millionth of a meter).

Think of it this way: a molecule is like a single brick, while a cell is like a whole house built from many bricks.