What are the key differences between applying an oil-based stain and a water-based polyurethane finish on wood surfaces?

Oil-based stains penetrate the wood to add color and enhance the grain, while water-based polyurethane finishes create a protective layer on the surface. Oil-based stains require longer drying times and emit stronger odors, while water-based polyurethane finishes dry faster and have lower odor levels. Oil-based stains may provide a richer color, but water-based polyurethane finishes are more environmentally friendly and easier to clean up.