Data modelling - Document
Data dictionary
A reference that explains the fields in a set of data and what each one means
What's it for?
Gives everyone the same plain definition of important data fields so numbers are understood consistently.
For example…
The dictionary states “active customer” means purchased in the last 12 months, not merely has a login
A data dictionary explains that “OrderDate” means the date an order was submitted, not when it was shipped or paid.
Think of it like…
Legend on a map telling you what each symbol stands for