The engine oil Lubrication system is used to distribute oil, to the moving parts to reduce friction between surfaces.
Above all, Lubrication plays a key role in the life expectancy, of an automotive engine.
So, if the lubricating system fails, an engine would succumb to overheating, and seizing quickly.
Many changes in engine oil and Lubrication requirements, have been seen in recent years. But, the basic theory of oil flow through the engine has hardly been modified, since the early days of driving. Also, the marvel of hydraulics remains the same. A lot of the shift has been from oil flow, to oil volume. More oil means, less overall engine wear.