What triggers a pipeline in Continuous Integration?

In Continuous Integration (CI), a pipeline is typically triggered by events that indicate changes to the source code that need to be integrated or tested. One of the most common triggers for initiating a pipeline is the creation of a Merge (Pull) Request. This action signifies that a developer has completed work on a feature or a fix in a separate branch and is ready to merge that work back into the main codebase.

The purpose of this trigger is to ensure that any new code added to the shared repository is built, tested, and validated before it becomes part of the main code. When a Merge Request is created, the CI pipeline will automatically run the defined series of jobs or stages to check for any issues, which helps maintain code quality and integration integrity across the team.

While other activities like a successful build or user approval are important in the workflow, they do not directly initiate the pipeline process in the same way that a Merge Request does. A code review is also a critical component of the development cycle but is typically an activity that occurs post-Merge Request before finalizing the integration.