Let's learn about Google Cloud Function triggers. Whenever you create a response to an event that was invoked when new files are added to Google Cloud Storage or whenever a new message is published to Google Cloud Pub/Sub, it is called a trigger. A trigger on a Google Cloud Function is a declaration/definition stating that you want the Google Cloud Function to be invoked in response to a certain set of events. You need to associate the Google Cloud Function to a trigger, which allows you to act upon the events that invoked the Google Cloud Function.
Triggers and Functions are associated with each other on a many-to-one basis. You can only have one trigger on a Google Cloud Function. However, you can have multiple Google Cloud Functions invoked from the same cloud event within the Google Cloud Platform.
Let's take a look at different triggers that are available...