Okay kiddo, let me tell you about steam fields. Imagine a big pot of water on the stove. When we heat the water on the stove, it starts to bubble and turn into steam (which is just water in gas form). A steam field is kind of like that pot of water, but it's happening deep inside the earth.
There are some parts of the earth where hot rocks and magma (which is melted rock) are close to the surface. When water seeps down into those rocks, it starts to heat up and turn into steam, just like the water in our pot on the stove. The steam then rises back up to the surface and escapes into the air.
People can use this steam for all sorts of things, like making electricity or heating buildings. Imagine if we could take the steam from our pot on the stove and put it through a machine that turns it into electricity. That's kind of what we do with the steam from the steam fields.
So, steam fields are like big pots of water under the ground, where hot rocks and water mix together to create steam. We can use that steam to do all sorts of cool things!