database
A structured place to store and query your app’s data, like users, purchases, and settings.
Like a filing cabinet with labeled folders and neat sheets inside. A database keeps records, which are rows of related details about one thing, in tables, which are named lists of rows that share the same columns.
It matters because your app must remember things between sessions and across devices. Supabase gives you a hosted Postgres database and accounts, so your app can sign people in and save their data.
In practice you design tables such as users, subscriptions, and messages. The app talks to the database through an API, which is a door on the internet that receives requests and sends back answers.