It is often used to describe things that move smoothly back and forth, like:
* Sliding doors: "portes coulissantes"
* Sliding windows: "fenêtres coulissantes"
* Drawer: "tiroir coulissant"
It can also refer to something that is movable or adjustable, like:
* Sliding scale: "échelle coulissante"
It's important to note that "coulissant" is an adjective, so it will usually modify another noun.