Creating reusable components
App makers build their canvas apps using a set of controls and components that are already available within Power Apps Studio.
Reusable components are a good way to create your own set of controls to be used within your app with custom parameters and behavior. It makes it easier for app makers to quickly create, maintain, and share their building blocks across screens and apps.
The anatomy of a reusable component
A reusable component is a set of existing controls reorganized and grouped in a container that can contain input and output properties, which will be responsible, respectively, for receiving data from outside and sending data from the inside:
When adding a custom property, you can select whether it will be an input or output property, and then define the nature of this property so that your app understands what it should receive/send: