A spreadsheet with rules.
A database stores your app's data so it's still there tomorrow, and so more than one person can use it at once.
id
name
phone
branch101
T. Mokoena
082 555 0101
Sandton
102
A. Naidoo
072 555 0102
Durban
103
J. Smit
083 555 0103
Cape Town
Table = a sheet. Row = one record. Column = one field. Primary key (id) = a unique number per row. Relationship = linking tables, like customers to their orders.
Where to keep data
In the browser: just you, one device.
A single file (SQLite): one small app.
A hosted database (e.g. Postgres): real users, shared data.
Source: POPIA ↗
Store what you need. Nothing more.