Let me clarify, the equator is the nearest place of the earth from the sun if compared to the distance of the north and south poles. Since the equator is nearest to the sun, it receives more rays of the sun, thus, receive more heat. Since the north and south poles are farther from the equator which is the place that is nearest tot the sun, it means that they are farther from the sun, thus, they receiver lesser rays and receive lesser heat.
