Explain/describe why there are seasonal changes on Earth?

Earth's angle with the sun. Light bends. Like if it is summer the earth is directly heating the earth like regions near the equator. If its winter it happens in parts where light bends and reflects due to the curvature of the earth's surface like north and south pole. When the sun's light goes through the earth the earths angle, revolution around the sun and its rotation on its axis; 4 seasons are made.