What triggers the automatic build and deployment process when code changes in a CI/CD system?

The process of automatic build and deployment in a CI/CD system is triggered by an event — a change in the code. Usually, this is a commit or push to a repository, for example, to the main or develop branch. The system monitors these events and automatically starts a pipeline when they occur, which performs build, testing, and deployment. Thus, changes in the code serve as a signal to start the entire process.