Sunscreen is one of the most important — if not the most important —  skincare products in your arsenal. Choosing a sunscreen with broad-spectrum protection and an SPF of at least 30 can help reduce the appearance of premature skin aging caused by the sun’s harmful UV rays, as well as reduce the risk of skin cancer. Speaking of skin cancer, did you know that according to the Skin Cancer Foundation, one in five Americans will develop skin cancerin their lifetime? With a probability like that, why wouldn’t you apply (and reapply) sunscreen daily? To help you further understand the importance of applying sunscreen, we’re breaking down how UV rays work, what SPF actually means and more. UV Rays 101While warm sun rays may feel good on your skin, they’re actually doing more harm than good — especially if you’re not wearing sunscreen. From wrinkles and sun spots to more serious issues like skin cancer, the side effects of UV rays are nothing to joke about, which is why you should be wearing sunscreen every single day, even when it’s cloudy outside. What Does SPF Mean?SPF, which stands for sun protection factor, is based on time. This means that the SPF number you see on your sunscreen bottle is a measure of how long your skin can be in direct sunlight without beginning to get red or getting a sunburn. Another important thing to know about SPF is that it measures UVB rays — the type of UV rays that burn the skin — but the sun also emits UVA rays, which can be equally as dangerous. When it comes to protecting your skin, cover your bases with a broad-spectrum sunscreen (which shields against both types of rays) like the La Roche-Posay Anthelios Ultra Light Fluid Facial Sunscreen SPF 60.What’s the Difference Between Chemical and Physical Sunscreen?Sun protection comes in two main forms: physical and chemical. Physical sunscreen (also known as mineral sunscreen) contains active mineral ingredients like zinc oxide and/or titanium dioxide. These two ingredients offer broad-spectrum coverage and work by blocking UV rays. Chemical sunscreen contains carbon-based active ingredients, such as octocrylene and avobenzone, which absorb UV light.  For a physical sunscreen, try the Vichy Capital Soliel Tinted 100% Mineral Sunscreen SPF 60 and for a chemical option, try the Black Girl Sunscreen SPF 30, which is free of common sunscreen ingredients oxybenzone and octinoxate, so it’s reef-safe.How Much Sunscreen Should You Apply?Has your sunscreen bottle lasted you for years and years? There’s a good chance you’re not applying the recommended amount (not to mention your formula is likely expired). You’ll want to apply at least one ounce — enough to fill up a shot glass — to cover all exposed parts of the body. Reapply at least every two hours, especially if you plan to sweat excessively or go for a swim. If you’re spending the day at the beach or pool, it’s a good idea to reach for water-resistant sunscreen. Water-resistant means that the sunscreen works for up to 40 or 80 minutes while swimming or sweating.What’s the Difference Between Sunscreen Formulas? Creams: If you have dry skin, try a cream-based sunscreen that contains nourishing ingredients like the La Roche-Posay Anthelios Mineral SPF Moisturizer with Hyaluronic Acid.  Lotions: Lotions are great for use on larger areas of skin. They also tend to be thinner and less greasy as compared to creams. Our go-to lotion is the La Roche-Posay Anthelios Melt in Sunscreen Milk SPF 60.  Gels: Gels can be refreshing and typically wear well under makeup. An editor favorite is the Lancôme UV Expert Aquagel Sunscreen with SPF 50. Sticks: To apply sunscreen around the contours of the face or for an on-the-go, mess-free application, a sunscreen in stick-form like the CeraVe Sunscreen Stick SPF 50 can be useful. Sprays: For hard-to-reach areas, a spray-on sunscreen can make application easier. A good way to ensure you’ve covered every spot is by applying sunscreen with a cream or lotion-based formula and following up with a spray like the COOLA Organic Body Sunscreen Spray as a backup.   Photo: Chanute VaughnRead More:How Much Sunscreen Should I Use on My Face and Body?The Secret to a Year-Round Glow? SunscreenThe Best Eye Creams With SPF to Try 
