CircleCI Configuration Visualization

I’ve heard from some people that they don’t quite understand the relationship between CircleCI concepts like pipelines, workflows, jobs, and steps. The first of which is brand new to CircleCI. Here’s a visualization (or diagram) of these CircleCI concepts and how they fit together.

The visualization above is a low resolution version. You can find a high resolution version here as well as the PDF version here.

Here’s a brief explanation of the terms:

pipeline - This is an instance of running a CircleCI configuration (config) file. It is not defined in the config itself but the result of running workflows in the config when there is a trigger.

trigger - Something that causes a pipeline to run. The trigger is most commonly a git push to a VCS provider such as GitHub. It can also be a Scheduled Workflow or an API call.

workflow - A workflow runs a git commit (via a branch or tag) through an ordered set of jobs. Jobs can be organized in parallel and/or many levels of hierarchy.

job - A collection of steps that will run in a specified execution environment (executor). Either a Docker container or a virtual machine (VM).

step - The smallest unit in a CircleCI pipeline, it runs shell commands. These shell commands are typically Bash commands but a step can be configured to run something else. In CircleCI Orbs, steps go by the name commands instead but they work the same.

This is my personal explanation on how this all works. You can go straight to the source and learn more at CircleCI Docs.