Earth has two different types of motions. Earth rotates on its own axis and this type of motion is called rotation. Earth also rotates around the sun in an elliptical orbit and such motion is called a revolution. Earth carries out both the motions simultaneously. In other words, earth rotates around the sun while rotating on its own axis. Earth rotates on its own axis, in a counter-clockwise fashion and completes one rotation in almost 24 hours, which is the duration of 1 earth day. This rotation is the reason we have night and day. Earth also revolves around the sun and takes almost 365 days to cover one complete revolution. It is the revolution of earth which is responsible for our seasons. By convention, our seasons change on either solstices (longest and shortest days) or equinox (day with equal duration of night and day). Thus the two motions of Earth are responsible for our night and day and the different seasons.
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