Okay kiddo, have you ever seen a big machine that cuts trees into planks and boards? That's called a sawmill. But imagine if you could take that machine with you wherever you go - that's a portable sawmill!
It's a bit like a big truck, but instead of carrying stuff, it carries a saw blade and a bunch of other equipment for cutting trees. It's like having a whole factory with you, but smaller and easier to move around.
When the sawmill gets to a forest or a different site where lots of trees need to be cut, it gets set up and turned on. The saw blade starts spinning really fast and cuts into the tree, making it into smaller pieces of wood. These pieces can then be used to make houses, furniture, and lots of other things!
The best thing about portable sawmills is that they can go to places that regular sawmills can't. Instead of needing to move the trees to the mill, the mill can come to the trees. This saves a lot of time and effort, and means that more trees can be cut down in a responsible way.
So there you have it, a portable sawmill is a special machine that cuts trees into smaller pieces of wood and can be moved from place to place so that the trees don't have to be - all to make cool stuff like houses and furniture!