Here's why this is important:

* Defining an element: The number of protons is what defines an element. For example, all atoms with 6 protons are carbon atoms.

* Electrons in a neutral atom: In a neutral atom, the number of protons (positive charge) is equal to the number of electrons (negative charge). So, the atomic number also indirectly tells you the number of electrons in a neutral atom.

Important Note: The atomic number does not tell you the number of neutrons. The number of neutrons can vary within an element, creating isotopes.