The Mohorovičić discontinuity, often referred to as the Moho, is the boundary between the Earth's crust and the underlying mantle. It is named after the Croatian seismologist Andrija Mohorovičić, who discovered it in 1909. This discontinuity marks a significant change in the composition and properties of the Earth's materials, as the crust is primarily composed of lighter rocks, while the mantle consists of denser, more solid materials. The Moho is located at varying depths beneath the Earth's surface, typically around 5 to 10 kilometers beneath the ocean floor and about 30 to 50 kilometers beneath continental regions. Seismic waves travel at different speeds through the crust and mantle, allowing scientists to identify this boundary. Understanding the Moho is crucial for studying the Earth's internal structure and geological processes.