A common way to combine data sources is showing how two data sources relate. Taking a look at the data sources of our app, you can see that I've added a departments list. This departments list contains the same departments as the items or employees inside of our employees list. To show an example of how we can combine these data sources, let's create a dropdown of departments, and then filter the employee list based on the selected department.

First, I'll add a dropdown and for its data source select our departments list. The value property will show which field the drop down will be showing, since there could be multiple fields. I'll select Department. Next, we'll look at our gallery of employees. In the items property, I'll change the filter to Department equals, and here is where we can reference our dropdown control. I can see that my dropdown control's name is Dropdown1. I'll type in Dropdown1 and then to reference the selected item I'll say "Selected". Since the selected item could have more fields associated with it, I'll need to specify that I want the Department field of the selected item. And now you can see that the gallery is being filtered based off of our selected item in the departments list. I could also combine these data sources by having a gallery of all the departments and then for each department show all of the employees that are inside of that department. This, however, would go beyond this introductory course on Power Apps. 

In the next lecture, we'll cover sharing and publishing your canvas apps.