What is a database, and how is it different from a spreadsheet?
A spreadsheet is a grid of cells you manipulate directly. A database is a structured store with enforced rules, designed for many users, large volumes and guaranteed consistency.
Where a spreadsheet is genuinely better: exploratory analysis, one-off calculations, small datasets, and anything where a human needs to see and manipulate everything at once. Spreadsheets are extraordinarily flexible, and that flexibility is the point.
Where the differences become critical:
Data integrity. A database enforces types — a date column accepts only dates — and constraints: values that must be unique, fields that cannot be empty, and referential integrity ensuring an order cannot reference a customer that does not exist. A spreadsheet lets you type anything anywhere, so a single typed character in a numeric column breaks calculations silently.
Concurrent access. Databases handle many simultaneous users with transactions — operations that complete entirely or not at all, so a transfer never debits one account without crediting the other. Spreadsheets handle concurrency poorly, and the result is usually a folder of files named final_v3_JS_edited.
Scale. Spreadsheets have row limits and slow dramatically well before them. Databases handle millions of rows routinely, using indexes to find records without scanning everything.
Querying. SQL expresses complex questions across related tables precisely and repeatably. Doing the equivalent with nested lookups is fragile.
Structure through relationships. Data is split into linked tables so each fact is stored once. A spreadsheet typically repeats a customer's address on every order line — and updating it means finding every instance.
Audit and access control at row and column level.
The real-world consequence. Spreadsheet errors in consequential settings are well documented — including the Public Health England case where case data was lost because an older file format's row limit was exceeded silently.
The rule of thumb: when several people need it, when it must be right, or when it keeps growing, it wants a database.