A transform boundary is a type of plate boundary where two tectonic plates slide past each other horizontally. Transform boundaries are significant in plate tectonics for understanding the movement and interaction of tectonic plates, as well as the formation of earthquakes along these boundaries.
Reference: Gordon, R. G., & Stein, S. (1992). “Global Tectonics and the Wilson Cycle.” Geological Society of America Bulletin, 104(8), 1073-1083.