If you need to Sign Out from AWS, you need to select "AWS Sign Out" in Add-ons menu.
"Refresh Current" functionality will allow you to refresh the report at currently opened sheet.
"Refresh All" functionality will allow you to refresh all reports in the current Google Sheets. This refresh will be in one by one sequence.
By using "Schedule Automatic Refresh" functionality you have the ability to set up the time when all your reports should be refreshed. You also have the ability to setup email notification and alerts to notify third party in case of metadata changes.