Things that refract light — like lenses and prisms — bend it. If you've looked through a water droplet on a car windshield, you've seen water refract light.
You're most likely to come across the verb refract when you're studying physics and the properties of light waves. We come across examples of this everyday, though — when you study a straw in a glass of water, you see the water refract light in a way that makes the straw look bent or jagged. A rainbow also happens when raindrops refract light, breaking it into its component colors. In Latin, refract means "broken up."