Service Accounts have arrived- Google Developers Blog
Mar 20, 2012

Summary
Introduced Service Accounts as a new method for applications to authenticate with Google APIs, allowing them to access user data without requiring user interaction. This enhances security and enables server-to-server communication.
More from the Federated Login and Identity Management trail
- Enhance Security and Trust: New Session Metadata in Sign in with Google- Google Developers Blog
- Supporting Google Account username change in your app- Google Developers Blog
- Usability and safety updates to Google Auth Platform- Google Developers Blog
- Chrome on Android to support third-party autofill services natively- Google Developers Blog
- Federated Credential Management (FedCM) Migration for Google Identity Services- Google Developers Blog