ELI5: Oil Paint vs Acrylic Paint: What's the Difference?

The main difference is that acrylic paint dries very fast using water, while oil paint dries very slowly using oil.

Think of painting like making a snack in your everyday life:

• Acrylic Paint is like making instant oatmeal: It is fast, easy, and mixes with plain tap water. When you put it on paper, it dries in just a few minutes, just like spilled water dries up on a warm kitchen counter. Because it dries so quickly, you can paint over a mistake almost right away. When you are done, you can clean your brushes at the sink using regular soap and warm water.
• Oil Paint is like spreading thick honey or butter: It is smooth, rich, and stays wet for days or even weeks. Because it stays wet so long, you have plenty of time to slowly blend colors together, just like mixing two colors of play dough. But because it is made of oil, water cannot wash it away. If you get it on your hands or brushes, you need a special cleaner, just like you need extra soap to scrub greasy butter off a frying pan.

• Drying Time: Acrylic is ready to touch in minutes, while oil takes days to dry.
• Cleaning Up: Acrylic washes off with plain water, but oil needs special paint thinner.
• Smell: Acrylic has almost no smell, but oil paint can have a strong scent that needs an open window.