A system that records every code change, who made it and when, and lets you compare or return to any earlier version.
Version control, best known through Git and GitHub, records every change to the code as a saved point with a description. You can see what changed between two versions, go back to last week's code and build a new feature on a separate branch without touching the live version.
For a founder, version control means safety and ownership: the code lives in a repository you own, and any developer can later understand its history and continue the work. With AI, it lets you review every change the agent made and undo it if needed. Practical tip: make sure your building tool lets you export the code to GitHub or a repository you own. Never store passwords or API keys in the repository; keep them in secret environment settings.