Oceanic plates are large sections of the Earth's lithosphere that make up the ocean floor. These plates are primarily composed of basalt, a dense volcanic rock, and are generally thinner than continental plates. They play a crucial role in the movement of tectonic plates, which can lead to geological events such as earthquakes and volcanic eruptions. The boundaries of oceanic plates can be divergent, convergent, or transform. At divergent boundaries, plates move apart, creating new oceanic crust through volcanic activity. Convergent boundaries occur when an oceanic plate collides with a continental plate or another oceanic plate, often leading to subduction, where one plate is forced beneath another, forming features like trenches and island arcs.