The Variables View is located below the Step View. The Variables View is separated from the Step View using a divider, which you can drag either up or down to make more room for one of the views.
The Variables View is divided into a left part and a right part with a similar divider. The left part shows the variables in a list. When you select a variable in this list, the details of that particular variable is shown in the right part of the view. The view shows the variable's values at the current step of robot execution, and these cannot be edited.
You can add or remove variables by right-clicking the list of variables. This displays a menu of variable types that can be added to the list. The menu also makes it possible to remove the selected variable.
You can edit the initial values of the variables by pressing the "Edit" button or double-clicking the variable list. This will open a dialog which looks very much like the Variables View and works in the same way. The important difference is that the dialog displays the values of the variables before any step has been executed, and these values can be edited.
Initial values for input variables are used when writing and testing the robot. When a robot is run in production, the input variables will be initialized to values determined by the application running the robot (if the application does not provide values, the robot run will fail).
Initial values for variables are the values that they will have at the start of the robot, i.e. at the first step. The values apply both when you are writing, testing, and running the robot in production.