There is a lot more that we can do with Playgrounds, and we have only scratched the surface in our quick introduction here. Before we leave this brief introduction, let's take a look at what Playgrounds are not so that we can better understand when not to use Playgrounds:
- Playgrounds should not be used for performance testing: The performance you see from any code that is run in a Playground is not representative of how fast the code will run when it is in your project.
- Playgrounds do not support on-device execution. You cannot run the code that is present in a Playground as an external application or on an external device.