Forging temperature is the temperature at which a metal needs to be heated up in order to bend it or hammer it into shape. Imagine you have some Play-Doh, and you want to make a toy car out of it. You can't just start bending it into shape right away, because it will be too hard and might break. But if you warm it up a little bit first, it becomes softer and more pliable, so you can mold it into the shape you want.
It's the same thing with metal. If you want to make a metal part or tool by hammering it into shape, you need to heat it up to a certain temperature first. This temperature depends on the type of metal you're working with and the specific forging process you're using. Sometimes, you might need to heat the metal up to over 1,000 degrees Fahrenheit!
Once the metal is heated up to the right temperature, it becomes more malleable and easier to work with. You can use hammers, presses, or other tools to shape the metal into whatever form you need. And once you're done, you can cool the metal back down and it will be strong and solid again, just in a different shape.