Version control records changes so people can review their history. Tests check chosen behaviors. Review checks the change before deployment, which makes it available in an environment. Monitoring checks what happens afterward. Passing tests cannot prove there are no bugs.
Worked example
A team changes a button label, runs tests and asks a teammate to review it. Only then does it deploy the approved version. If monitoring finds a problem, the team pauses and investigates rather than guessing that tests cover everything.
Paper Release Plan
Put these steps on paper: record a small change, run tests, review, deploy, monitor. Our pretend team requires all five in that order. One test checks that the button opens the intended worksheet. These are planning exercises only; do not change or deploy a real site.