Final answer:
Joints are the most common structural features of rocks, being planes of weakness, unlike faults which are fractures with significant movement.
Step-by-step explanation:
Joints are the most common structural features of rocks. They are planes of weakness where the rock tends to break more easily but have not shown significant movement as opposed to faults. This can be contrasted with faults, which are fractures in the rocks that have had significant movement along them, often associated with earthquakes and other tectonic processes such as continental drift, mountain building, and volcanic eruptions. While faults are indeed significant structural features, they are generally less common than joints.
Other features like solution cavities are related to the erosion of soluble rocks, such as limestone, leading to natural formations like caves. Lava vesicles are created by gas bubbles in volcanic rocks, but these are specific to volcanic environments and thus not as widespread as joints.