What distinguishes an exoplanet from a planet in our solar system?

An exoplanet is defined as a planet that orbits a star outside of our solar system. This distinction is crucial because it separates exoplanets from the planets that are part of our own solar system, such as Earth, Mars, and Jupiter, which all orbit the Sun. The study of exoplanets has greatly expanded our understanding of planetary systems and the variety of conditions under which planets can form and exist in the universe.

The concept of exoplanets has become particularly significant with the discovery of thousands of these celestial bodies, which are located around other stars, revealing the complexity and diversity of planetary systems beyond our own. This differentiates them clearly from the known planets, which all revolve around our Sun.