Oil-based paints are more traditional or older style paints for wood & metal. Oil-based paints generally have a higher odour and longer drying time. If using white oil based paints they may yellow over time do to the “oil” or “polyurethane” present.
Water-based wood & metals paints are generally lower odour, quicker drying and easier to clean up than their oil-based equivalents. Water-based technology has improved greatly over the last number of years and most contain alkyld resins meaning they feature similar or equal durability to oil-based paints but without the higher odour or more difficult clean up!