How can automatic process activation be implemented using triggers in a pipeline?

Automatic activation of processes in a pipeline can be implemented using triggers that initiate specific stages when certain events occur. For example, in CI/CD systems (Jenkins, GitLab CI), a trigger could be a commit to the repository, creation of a pull request, or successful completion of the previous step.

Example in GitLab CI:

stages:
  - build
  - test

build_job:
  stage: build
  script:
    - ./build.sh

test_job:
  stage: test
  script:
    - ./run_tests.sh
  when: on_success  # Automatically runs after successful build_job

Thus, triggers allow automating process launches without manual intervention.