What are CI/CD pipelines?
A CI/CD pipeline tests, builds, and ships the app after every push.
What it is
A pipeline is a chain of automatic steps after a push. CI, continuous integration, checks and builds: tests, lint, an image, a version. CD, continuous delivery or deployment, ships that build to an environment you have named.
The push is the trigger. Everything that should happen after it lives in the pipeline, not in a sequence someone has to remember.
What it is made of
Without a pipeline you build and copy by hand. Each step can turn out differently from the last time, because a dependency on the laptop was newer or a command was missing. With a pipeline the path is the same, no matter who made the push.
What goes wrong
A push to main is the signal on MainPath to start that chain. The state in the repository is the state that gets built, not the folder someone has open. If a step fails, nothing is shipped. That is the point: better red in the pipeline than broken in production.
What you otherwise look after yourself
The pipeline needs access to store images and to reach the server. That access lives as protected variables, not in the log. A log that prints tokens is a leak.
How it shows up on MainPath
What happens in the chain is described under What are pipelines. You do not maintain a private list of commands for every project that only one person knows.