The innermost section of the Earth is the core. The core is the central part of the Earth and is located beneath the mantle. It is the hottest and densest part of the Earth, and it consists of two layers: the outer core and the inner core.
The outer core is a liquid layer that surrounds the inner core. It is composed mostly of iron and nickel, and it generates the Earth's magnetic field through the movement of electrically charged particles. The inner core, on the other hand, is a solid layer that is composed mostly of iron and nickel. It is under immense pressure and is extremely hot, with temperatures reaching up to 5,500 °C.
The core is the source of the Earth's internal heat, which drives plate tectonics and the movement of the continents. It is also responsible for the formation of the Earth's magnetic field, which protects the Earth from harmful solar radiation.
In summary, the innermost section of the Earth is the core, which is composed of two layers: the outer core and the inner core. The core is responsible for generating the Earth's magnetic field, providing the Earth's internal heat, and driving plate tectonics.