Explain · Like I'm five version
Plate tectonics in terms of a trifle
Do you know that the ground underneath your feet is just like a big, wobbly bowl of trifle?
The Earth is made of giant pieces of rock called plates, and they sit on top of a gooey, hot layer called the mantle. Think of the Earth like a bowl where the plates are big chunks of sponge cake, and the hot mantle is the thick custard underneath. Just like the sponge cake slides around on top of the custard if you tilt your bowl, these big plates move very slowly across the hot, sticky rock below them. It takes a very, very long time for them to slide, unlike the cake which moves the moment you wobble the bowl.
Sometimes these plates slide past each other, which can make the ground shake. This is just like when the bits of fruit in your trifle get bumped into each other. When two plates crash together, they might push upwards to make a big, bumpy mountain. It is exactly like when you pile up extra jelly and cream to make a fancy heap on top of your pudding. If one plate slides under another, it gets pushed down into the hot custard and melts away, just like a soggy biscuit disappearing into a puddle of jam.
Because these plates never stop moving, the map of the world is always changing. It is like a kitchen where the dessert is being rebuilt every single day for millions of years. New land is made where the plates pull apart, like adding fresh custard to fill a gap, and volcanoes erupt to add even more layers to our giant, spinning, stony pudding.
Where the analogy breaks downThe Earth is much, much hotter than a pudding and would definitely melt your spoon.