This is one of the most common Google Cloud interview questions. Service accounts are the special accounts related to a project. They are used for the authorization of Google Compute Engine in order to be able to perform on behalf of the user thus receiving access to non-sensitive data.
There are different service accounts offered by Google but mainly, users prefer to use Google Cloud Platform Console and Google Compute Engine service accounts.
The user doesn’t need to create a service account manually. It is automatically created by the Compute Engine whenever a new instance is created. Google Compute Engine also specifies the scope of the service account for that particular instance when it is created.