schema
Like a floor plan for a warehouse, it says what shelves exist, what fits where, and how pieces relate.
Picture a floor plan that names rooms and where doors connect. A database schema is the map of your data: tables, their columns, and the links between them.
It forces order so your app and your data agree. When the schema is clear, your AI agent and teammates avoid guessing column names and data shapes.
In Supabase you shape the schema by adding tables and columns, setting types like text or number, and adding foreign keys, which are links from one table to another. Changes are called migrations, saved steps you can replay.