A rod pump is a type of artificial lift system used in the oil and gas industry to extract crude oil from underground reservoirs. It consists of a long metal rod connected to a pump at the bottom of the well, which moves up and down to create pressure that brings oil to the surface. This method is particularly effective in wells where natural pressure is insufficient to push the oil out. The rod pump operates through a mechanical system that includes a surface unit, a polished rod, and a downhole pump. As the surface unit moves the rod, it activates the pump, allowing oil to flow through the tubing to the surface. This technology is widely used due to its reliability and efficiency in various geological conditions.