deployment
The act of taking code that works on your machine and making it run for real where users can reach it.
Like opening day at a shop after the shelves are stocked and the sign is up. Deployment is publishing your app or service to a live place: app stores for mobile apps, and servers for back‑end jobs and websites.
It matters because until you deploy, no one can use your work. This step adds settings for each place, called configuration, and secrets, which are private keys that identify and protect your services.