A transform boundary, also known as a transform fault, is a type of plate boundary where two tectonic plates move past each other horizontally. The motion at a transform fault is classified into two categories: right-lateral and left-lateral. Transform boundaries are also known as conservative plate boundaries because they involve no addition or loss of lithosphere at the Earths surface. Transform faults are commonly found linking segments of divergent boundaries (mid-oceanic ridges or spreading centers) . The grinding action between the plates at a transform plate boundary results in shallow earthquakes, large lateral displacement of rock, and a broad zone of crustal deformation. The San Andreas Fault is the most famous example of a transform boundary on land.