Okay, so imagine you have a big, heavy rock that you want to change its shape. Maybe you want to make it flatter, or thinner, or pointier. But you can't do it with your hands because the rock is too tough. That's where an Anvil comes in handy!
An Anvil is like a special table made of metal that is very heavy and hard. It's kind of like a super-strong hammering tool that is used to shape metal, like a blacksmith would do.
When you have a piece of metal you want to shape, you put it on the Anvil and then use a hammer to hit it. The Anvil helps to make the metal firm and steady so that it doesn't move around when you're hitting it.
The surface of an Anvil is also specially designed to help shape the metal in specific ways. Sometimes it will have a flat surface and other times it will have a curved one, depending on what the blacksmith wants to make.
In simpler words, an Anvil is like a tough metal table that helps blacksmiths shape metal by holding it in place while they whack it with a hammer!