Okay kiddo, have you ever seen a glass window or a glass jar? That's made of something called "factory glass".
So, imagine you have some sand. Now, sand is made of tiny pieces of rock called "silica". To make factory glass, we first need to turn the silica sand into a liquid. We do this by heating it up really hot, almost as hot as lava!
Once the sand has turned into a hot liquid, we can put it into a machine called a "furnace". The furnace keeps the liquid hot and melts it even more.
Then, we can take the hot liquid glass and pour it into a special mold, which is kind of like a cookie cutter. The mold shapes the liquid glass into whatever shape we want - a flat rectangle for a window, or a round jar for storing things!
Finally, we cool the liquid glass down really quickly so it becomes a hard and solid shape, like the glass window or jar that you've seen before.
That's how factory glass is made - by heating up sand into a hot liquid, shaping it, and then quickly cooling it down to make it hard and solid!