The sodium-potassium pump was discovered in the 1950s by a Dutch doctor named Jens Christian Skou. He studied the nerves of crabs and became famous for buying 25000 crabs over the years from a local fisherman and boiling them to observe their nerve fibers.
On one side of the nervous cell membrane is a group of positively charged sodium ions, and on the other side are potassium ions. However, some sodium ions are on the potassium side and the other way around, and they have to get back to their respective sides.
That is where the Sodium-Potassium pump comes in. This micromachine is used by your cells to move molecules. They work by using ATP, the cells' currency, to generate power. The pump has three slots for sodium and two for potassium. When the ATP is inserted, the pump changes form and releases the sodium. Then, two potassium ions get in the pump, and it reverts to its original shape, taking them back to their side of the cell.
The sodium-potassium pump is important because we need sodium and potassium to be able to move around for different nervous processes like thinking or smelling.