Planetary tilt refers to the angle at which a planet's axis is tilted in relation to its orbit around the Sun. For example, Earth has a tilt of about 23.5 degrees. This tilt is responsible for the changing seasons, as different parts of the planet receive varying amounts of sunlight throughout the year. Different planets have different tilts. For instance, Mars has a tilt similar to Earth, while Uranus has an extreme tilt of about 98 degrees, causing it to rotate on its side. These variations in tilt affect climate and weather patterns on each planet.