Solar collectors are devices that capture sunlight and convert it into usable energy, typically for heating water or air. They are commonly used in residential and commercial settings to provide hot water for domestic use or to heat swimming pools. The two main types of solar collectors are flat-plate collectors and evacuated tube collectors, each designed to maximize energy absorption. These collectors work by absorbing sunlight through a dark surface, which heats a fluid that circulates through the system. The heated fluid can then be used directly or stored for later use. Solar collectors contribute to renewable energy efforts and help reduce reliance on fossil fuels, promoting sustainability.