The general mechanism of an air compressor is a piston or rotary element (e.g. rotary screw or vane) that draws in Water Lubricated Air Compressor atmosphere, which is compressed right into a storage container. Naturally, because the piston or rotary component needs to move consistently and smoothly for this to work, it generally must be 
lubricated.
In a lubricated air compressor, there is lubricating oil which keeps the piston or rotary element running smoothly without damaging the system. The lubricant also really helps to dissipate warmth and keep maintaining air compression efficiency.
Oil-totally free air compressors also use a piston or rotary element, but they bypass the lubrication problem by coating the compression component with a pre-lubricating material like Teflon. Some oil-free compressors could also use water instead of oil for the lubricating and cooling procedure. These alternate materials defend the pump and invite the mechanism to go smoothly without the need for any oil-based or synthetic lubrication.