Action Potential

I keep learning about action potentials in all of my biology courses so far this semester. The professors always start off with the resting membrane potential of the cell. This is when the inside of the cell is negative compared to the outside. When there's a stimulus, the cell goes through depolarization as its first step. This is when the charge inside the cell becomes more positive that the outside. If and once the cell reaches threshold, an action potential will occur. The cell will then go through repolarization where it starts becoming more negative again. The next step is hyperpolarization which is when the cell becomes even more negative than it was at its resting membrane potential. The cell finally goes back to its resting membrane potential until another stimulus makes it reach threshold again.