SPF stands for Sun Protection Factor. It is a measure used worldwide to indicate the level of sunscreen protection. Using an SPF 15 sunscreen means it will take 15 times longer for skin to begin to burn than it would without sunscreen.
There are two types of ultraviolet (UV) light that can harm your skin- UVA and UVB. A Broad Spectrum sunscreen protects you from both. UVB rays are primarily responsible for causing sunburn while UVA rays are associated with skin aging.
The recommended amount of sunscreen for the average person is 1 Fl Oz. A simple way to remember how much sunscreen to apply is imagine the amount of sunscreen that would fit in a shot glass or the size of a golf ball.
Sunscreen should be applied 15 minutes before sun exposure and reapplied every 2 hours or immediately after swimming, sweating or drying off.
There are two general types of sunscreen - traditional and mineral. Traditional sunscreens work by absorbing the sun's rays while mineral sunscreens protect skin by blocking the sun's rays. Whichever type you choose, make sure it provides Broad Spectrum UVA/UVB protection.