Variables
Variables are a fundamental part of any development approach, regardless of whether you are using Power Apps or you are developing using a programming language. They are used to store temporary copies of data so that they can be consumed by other areas of your app.
All variables are defined by the boundaries from which they can be accessed; that is, we can create variables that can only be accessed within a single screen or that can be accessed throughout the app. This is known as the scope of the variable.
Global variables
Global variables are scoped so that they can be accessed from anywhere within your app. Global variables are extremely versatile as you can store any type of data within them – that is, you can store tables of data as well as simple strings and numbers.
We use global variables where we want to be able to store the data once but potentially use it multiple times throughout our app. They could be used to store app-level data when the app first loads...