Fascinated by car technology, I decide to learn how an oil filter works
So here we go:
As you can see inside the sealing gasket is a plate with many holes. At the center of the gasket is a central hole which mates with the filter on the engine.
A filter membrane is to be found inside the can that is usually made of cellulose fibers. The engine’s pump takes the oil to the filter, where it gets into the perforations of the tapping gasket. The unfiltered oil then passes through the filter membrane and exits through the central hole after which it re-enters the engine as clean oil.
Having said it, you can see the importance of having a great oil filter so as to trap impurities and any other foreign object that may find its way inside. For more on oil filters, see best oil filter here.