This feels like a very stupid question to ask... but first the background:
Currently running through a SaaS questionnaire with a third party application for Jira Cloud and we received the following response to one of the questions:
Q: Which parties have access to data stored or processed within the cloud service?
A: Customer, vendor, and a third party
We queried why the vendor and a third party have access which came back as the app is stored on GCP and the vendor uses Atlassian API to access issue data without which will limit the functionality of the app.
So my actual question: When you add a third party application to a cloud site, what is actually happening in the background? Sounds like nothing is "installed" on the site and instead it's only opening access to an application which lives on another server? As a said, feels a fundamental/silly question but cannot find any clarification in Atlassian documentation on this.
We're only dipping our toes in the cloud pool as our main instance is data center so obviously we're very used to installing apps directly into our instance.