The document summarizes the internal structure of the Earth. It is divided into three main layers - the crust, mantle, and core. The crust is the outermost layer and is divided into continental and oceanic crust. Below the crust is the mantle, which extends from the Mohorovičić discontinuity to the Gutenberg discontinuity. The innermost layer is the core, which is divided into a liquid outer core and solid inner core.