Understanding control behaviors and actions
Before developing your production canvas app, try creating a blank test app or use one of the many great App templates available for free, and try out each control. Power Apps has lots of great controls designed to provide the best experience for both the maker and the end user. Controls have many different properties that you can modify to easily enhance the user experience without sacrificing functionality or performance. As you start to develop your production app, it's important to think not only about the purpose of the controls you incorporate and how they function, but also what actions occur when a user interacts with the control.
For example, a user selects a Button control initiating a sequence of actions or behaviors place changing the state of the app. That's because there's a formula in the OnSelect property of the Button control. By default, the value is false, but you can change it to many options to:
Refresh, update, or remove items in a data source - Refresh, Update, UpdateIf, Patch, Remove, and RemoveIf functions.
Update a context variable - UpdateContext function.
Create, update, or remove items in a collection - Collect, Clear, and ClearCollect functions.
This isn't an exhaustive list, by any means. A simple but popular example of using the OnSelect property of a control is to change screens when a user selects a control such as a button or an icon. The code would look similar to this example:
Navigate(Screen2,ScreenTransition.Cover)
In the code above, assuming your app has a screen named Screen2, selecting the control takes the user to Screen2 with a screen cover transition.
Other ways that you can enable users to control your app are with OnChange properties of drop downs, text inputs, date pickers, and radio button controls. The OnCheck of a check box control is another way to control your app. Again, experiment with these different controls to find the functionality you're looking for. Chances are, Power Apps has exactly what you're seeking after!