What does an LDR sensor do?

An LDR (Light Dependent Resistor) sensor is a type of resistor that changes its resistance based on the intensity of light it is exposed to. When light levels are high, the resistance decreases, allowing more current to flow, while in darkness, the resistance increases, reducing current flow. This property makes LDRs useful in various applications, such as automatic lighting systems, light level meters, and alarm systems that respond to changes in ambient light.