What does it mean low oil pressure?

All car engines have oil pumps in them to force the oil to circulate through the dozens of moving parts in the engines. This keeps the metal-to-metal friction of the moving parts at a minimum and also helps to reduce heat. Less friction and less heat extend the life of the engine. If the oil level in the engine gets too low, there won't be enough oil to sufficiently supply the lubricating needs of the engine. This level is detected in the engine by the oil light. If there is not enough oil, or if the oil pump is leaking or failing, the oil pressure from the pump will drop. Since this is dangerous to engine, the warning system picks up this condition, and turns on the warning light in the dashboard to let you know that a correction to this problem is required to keep your engine happy and healthy. If it is not corrected soon, the engine will began to self-destruct rapidly, from insufficient lubrication.