Google Trigger for Cloud build

Hello,

This question is related to QwikLabs, I am wondering what this script is doing wiht build triggers?

It’s in this lab cloudskillsboost.google/paths/83/course_templates/41/labs/520382

" Building a DevOps Pipeline "

steps:
  - name: 'gcr.io/cloud-builders/docker'
    args: ['build', '-t', 'REGION-docker.pkg.dev/Project ID/devops-repo/devops-image:$COMMIT_SHA', '.']
images:
  - 'REGION-docker.pkg.dev/Project ID/devops-repo/devops-image:$COMMIT_SHA'
options:
  logging: CLOUD_LOGGING_ONLY