Orbital period

Okay, let's imagine you're spinning around in circles while holding a ball on a string. The time it takes for you to do one complete spin and bring the ball back to where it started is the orbital period.

Now think about the Earth going around the Sun. The Earth takes 365.25 days to complete one full orbit around the Sun. That's the Earth's orbital period.

But not everything takes the same amount of time to go around the Sun. Mercury, for example, is closer to the Sun and goes around faster. It only takes 88 Earth days to complete one orbit. Meanwhile, Neptune is farther away and goes around slower. It takes 165 Earth years for Neptune to complete one orbit.

So, in summary, the orbital period is the time it takes for an object to complete one full orbit around another object.