A Near-Earth Asteroid (NEA) is an asteroid that orbits the Sun and comes close to Earth's orbit. These asteroids are classified based on their distance from the Sun and can be found in various regions of the solar system. NEAs are important for scientific study because they can provide insights into the early solar system and the formation of planets. Some NEAs have the potential to impact Earth, which raises concerns about planetary defense. Organizations like NASA monitor these asteroids to assess their trajectories and potential risks. Understanding NEAs helps scientists develop strategies to mitigate any future threats to our planet.