Okay, so imagine you are playing with some sand on a hillside. You might notice that the sand slips and slides down the hill pretty easily, right? But what if there were some plants growing on the hillside? Those plants would keep the sand in place and make it harder for it to slip and slide down the hill.
Well, the same thing happens in real life with big hills and mountains. When there are plants growing on them, like trees, bushes, and other green stuff, those plants help keep the earth in place and prevent big landslides or rockfalls.
This is because plants help hold the soil together with their roots, and they also help absorb water. When water seeps into the soil and makes it all wet, the soil can get really heavy and start to move down the slope. But if there are plants there, they can absorb some of that water, which makes the soil lighter and less likely to move.
So, basically, having lots of vegetation growing on slopes and hillsides is really important for preventing big landslides or rockfalls. It helps keep everything stable and safe for people who live nearby.