Day occurs when the side of the Earth is facing the sun, providing light, while night occurs on the side facing away, resulting in darkness. Nocturnal animals are active at night and sleep during the day. The sun gives us light and warmth during the day and powers many things on Earth. At night, the moon and stars can be seen, with the moon reflecting sunlight and stars being distant balls of gas. Different places on Earth experience night and day at opposite times due to the planet's rotation.