Because planets do not have nuclear fusion, they do not produce their own light. Instead, they shine with light reflected from a star. When we see planets in the night sky, such as Venus, the so-called "Evening Star," we're seeing reflected sunlight.

Which planet has their own light?

Planets do not have their own light; they appear bright due to reflection of sunlight by them. Unlike stars, planets are small in size and do not twinkle at night. The planet closest to Sun is Mercury which is followed by Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Does Jupiter have its own light?

The inner planets do not emit any of their own light. Instead, they are visible because they reflect sunlight. This is not strictly true for Jupiter. If you measure how much total light it emits, it is more than the amount of sunlight that reaches the planet.