Core
Core explained in an easy to understand way:
Imagine trying to find the source of warmth in a cozy, heated room on a cold winter day. Just like the heater is hidden away but essential for keeping the room warm, the Earth's core is hidden beneath layers but is crucial for the planet's heat. The heater in the room is analogous to the Earth's core, as both are central sources of heat that influence their surrounding environments, even though they are not directly visible.
Practice Version
Core: The central part of the Earth, below the mantle, is the core. The core is the innermost layer of Earth, made mostly of iron and nickel, and it's responsible for generating our planet's magnetic field.