Here's a breakdown:

* Orbit: A planet's orbit is the path it takes around its star.

* Revolution: One full trip around the star is called a revolution.

* Year: The time it takes for a planet to complete one revolution is its year.

Factors influencing the length of a year:

* Distance from the star: The further a planet is from its star, the longer the orbit and the longer its year. This is because the planet has to travel a greater distance.

* Star's gravity: The stronger the star's gravity, the faster the planet will orbit, resulting in a shorter year.

Example:

* Earth: It takes approximately 365.25 days for Earth to orbit the Sun. This is why we have a year that is about 365 days long.

* Mars: Mars is further from the Sun than Earth. It takes approximately 687 Earth days for Mars to complete one orbit, which is about twice as long as Earth's year.

Important Note: We measure the length of a year in Earth days, but each planet has its own unique time scale.