UV rays, or ultraviolet rays, are a type of electromagnetic radiation emitted by the sun. They are invisible to the human eye and are divided into three types: UVA, UVB, and UVC. UVA rays penetrate the skin more deeply and are primarily responsible for skin aging, while UVB rays are associated with sunburn and play a significant role in developing skin cancer. UVC rays are mostly absorbed by the Earth's atmosphere and do not reach the surface. Exposure to UV rays can have both positive and negative effects. On the positive side, they help the body produce vitamin D, which is essential for bone health. However, excessive exposure can lead to skin damage, eye problems, and an increased risk of skin cancer. It is important to protect the skin by using sunscreen and wearing protective clothing when spending time outdoors.