For the most part, we understand the importance of sunscreen when heading to the beach or spending time outside under the hot summer sun, but what about the during the rest of the year? You may think that in the Winter it's completely pointless to be wearing sunscreen, but that's not the case. In fact, the sun can be even more damaging to your skin when you least expect it. Even on a cloudy day, "up to 80% of the sun's rays can pass through". This is because there are two types of rays that are reaching you; Ultraviolet A rays and Ultraviolet B rays. So what's the difference between UVA and UVB rays?