Final answer:
Earth's axis tilts at approximately 23.5°, known as axial tilt or obliquity. This tilt affects seasonal changes and the annual solar path, and the axis precession modifies Earth's orientation over long periods.
Step-by-step explanation:
Earth's axis is not perpendicular to its orbital path. Instead, it tilts approximately 23.5°. This tilt is referred to as the axial tilt or obliquity, and it is significant because it influences the seasonal changes on Earth. The tilt of Earth's axis means that the plane of Earth's equator is inclined to the plane of the ecliptic, which is Earth's orbital path around the Sun, by about 23.5°. This inclination is also responsible for the perceived annual path of the Sun across the sky, which changes as Earth orbits the Sun.
The axis precession of Earth also plays a role in the long-term changes in our climate. This precession is a slow, conical motion of Earth's axis that makes one complete rotation approximately every 25,780 years. It slightly alters Earth's orientation to the Sun over millennia, leading to changes in the temporal patterns of the seasons.