1. Crust: The outermost layer, relatively thin and composed of mostly silicate minerals. It's further divided into the oceanic crust (thinner, denser, and younger) and the continental crust (thicker, less dense, and older).

2. Mantle: The thickest layer, making up about 84% of Earth's volume. It's primarily composed of silicate minerals but also contains iron and magnesium. It's largely solid but can behave like a viscous fluid over long geological timescales.

3. Core: The innermost layer, composed primarily of iron with a smaller proportion of nickel and trace amounts of other elements. It's divided into the outer core (liquid) and the inner core (solid) due to the immense pressure.

Let me know if you want to explore these layers in more detail!