The operation's name is a little confusing. It's not really a checkpoint when you are outputting values. This allows you to take text from your application (such as an edit field or a list box) and store it in your script or in the data table. The configuration GUI that appears when doing a standard output value is similar to a standard checkpoint. You select the property that contains the value to output, and then you specify the output destination such as a column in the data table.

You can then use this output value for input again later on in another script or you could save the data for another script to use later on.