Simply put, water-based stains are what you can thin just by adding some water, while oil-based stains often need specially-made oil to be able to penetrate into the wood.
Specifically, water-based stains include pigment and resin which will stick to each other after drying, and water-based besides common benefits is cheaper, less odor dries quickly, and easy to clean!
However, with this stain, you have no choice but to apply more than a coat on your wood, meaning it is not as economical and durable as the oil-based, except for the fact that, the water-based paints are better for mildew.
When it comes to oil-based stains, they are often more expensive than water-based but it lasts longer and enables it to preserve the wood surface better. There is more than one method to use with oil-based: spraying, rolling or brushing on, all works well
More excitingly, oil-based products are supposed to enhance the color of the wood, making it fresher when applying the coat.