Why is transform plate bounries often described as horizontal sliding?

Transform plate boundaries are often described as horizontal sliding because the tectonic plates move laterally past each other rather than colliding or pulling apart. This lateral movement occurs along faults, where the stress from the sliding motion can lead to earthquakes. The plates do not create or destroy crust at these boundaries, which distinguishes them from divergent and convergent boundaries. Instead, they shift horizontally, resulting in the characteristic geological features associated with transform boundaries.