Final answer:
The Moho is the boundary between the crust and the mantle, marking a seismic boundary between these layers of the Earth's interior.
Step-by-step explanation:
The Moho is the boundary between the crust and the mantle. The Earth's interior consists of the crust, mantle, outer core, and inner core. The Moho, also known as the Mohorovičić discontinuity, is a seismic boundary that separates the crust from the underlying mantle.