Okay, so imagine you go camping in the woods and there are lots of plants and trees around you. If you wanted to make a place to sleep, you might cut down some small trees or bushes and clear an area. But what about all the other plants around you? It would be a lot of work to cut down every single one.
That's where fire-stick farming comes in. Instead of cutting down all the plants, people who practice fire-stick farming use fire to clear the land. They start a small, controlled fire in a certain area and let it burn for a bit. The fire burns away all the dead leaves and other things on the ground, which makes it easier to walk around and find things like berries and nuts.
But the fire doesn't burn everything. Some plants have roots that go really deep into the ground, so they don't get hurt by the fire. And some plants actually need fire to grow better! When the fire burns away the dead things on the ground, it gives the soil some nutrients that help these special plants grow.
After the fire burns out, the people who practice fire-stick farming can go through and use the cleared land to grow things like crops or to hunt animals. And since they didn't have to cut down every plant by hand, it takes a lot less work!