Sun beds are devices designed to provide artificial ultraviolet (UV) radiation for tanning purposes. They typically consist of a fluorescent lamp that emits UVA and UVB rays, which can cause skin to darken in color. Sun beds are often used by people who want to achieve a tan without exposure to the sun's natural rays or in regions where sunlight is limited during certain times of year. However, excessive use of sun beds has been linked to health risks such as skin cancer and premature aging of the skin.