Final answer:
Plates slide horizontally past each other along transform plate boundaries, leading to seismic activity along faults.
Step-by-step explanation:
Plates are sliding past one another horizontally along a transform plate boundary. At transform boundaries, tectonic plates are not colliding or pulling apart from each other; instead, they slide horizontally past one another. This movement can lead to earthquakes along faults, which are fractures between two blocks of rock. An example of a transform plate boundary is the San Andreas Fault in California. This is in contrast to convergent boundaries, where plates move toward each other, potentially leading to subduction (one plate moving under another) or mountain-building, and divergent boundaries, where plates move apart from each other, allowing magma to rise and create new crust.