Freestyle (or park) skis are built specifically for terrain parks, halfpipes, and riding switch (backwards). They feature twin tips—both ends curve up—so you can land and ride in either direction. They also have symmetric geometry and reinforced edges to handle sliding on rails and boxes without falling apart.
These skis make sense if you spend most of your time in the park or if tricks and switch riding are a priority. They're typically softer and more playful, which makes spins, butters, and presses easier to initiate.
The trade-off is that freestyle skis are less stable at high speeds and don't float well in deep powder. If you split your time between the park and the rest of the mountain, an all-mountain ski with twin tips might be a better compromise. But if the park is your main scene, a dedicated freestyle ski will give you the tools you need where it counts.