Actions enable users to interact with your product or service right inside Gmail.
For instance, when you send a notification that a magazine subscription is about to expire, you can present the option to renew it right from the notification.
Actions can be declared in two ways: as In-App Actions or as Go-To Actions. Multiple types of actions are currently supported.
Go-To Actions take the user to your website where the action can be completed. Unlike
One Click Actions, go-to actions can be interacted with multiple times.