What causes pressure to build up inside the Earth?

Pressure builds up inside the Earth because heavy things are being squished together deep underground.

Imagine you're playing with your toy blocks. If you stack them one on top of another, the ones at the bottom feel really squeezed, that's like pressure! Now imagine doing this not just with blocks, but with huge slabs of rock and metal, all the way down to the center of our planet.

Deep inside the Earth, there are layers made of super-hot and super-dense stuff. These layers are being pushed together by the weight of everything above them, like when you press your hands together really hard. This pushing and squeezing makes the pressure go up.

The Earth is also full of molten rock, which moves around like hot soup. When this molten rock is squeezed from all sides, it can cause big changes, like when you squeeze a balloon too much and it pops! This pressure builds up until it's strong enough to make mountains rise or send lava bursting out.

So the Earth is always pressing down, and that pressure helps shape our planet in amazing ways.