What is outer core definition?

The outer core is a liquid layer that surrounds the Earth's solid inner core and is believed to be composed mainly of molten iron and nickel. It is about 2,250 km thick and is the second layer of the Earth's core. The temperature in the outer core is believed to be around 4,000-5,000 degrees Celsius, which is even hotter than the surface of the Sun. The outer core is responsible for generating the Earth's magnetic field through the process of a dynamo effect, where the motion of the molten metal creates electrical currents that produce magnetic fields. The outer core also plays a role in the plate tectonics, as it helps to drive the movement of the Earth's plates.