Database
also: databases, db
An organized place where an app stores information so it's still there later, like user accounts, orders or saved posts.
A system for storing, organizing and retrieving data reliably. Most apps use one, such as PostgreSQL or MongoDB, so data survives restarts and can be searched and updated safely by many users at once.
A database is a very well-organized records room. Everything has a place, you can find any document quickly, and it's all still there tomorrow even if the lights go out.
Your users' data lives in the database. Agent changes that touch it deserve extra care, because deleting or reshaping real data is much harder to undo than changing a page.
I'll add a notes field to the workouts in the database. Existing workouts will get an empty note, so no data is lost.
Before changing anything in the database, tell me exactly what will change and whether any existing customer data could be lost.
Thinking a database is just a big spreadsheet. It's similar in spirit, but built to handle many users, strict rules and large amounts of data safely at the same time.