**Facts are the money spent, [[Dimensions]] are where and when.**
Facts and dimensions both look like columns in a table, and they are, but they carry a different purpose.
Facts are the raw, usually numeric data. These are the things that retain meaning when you roll them up in a summary. Some facts are *additive*, meaning it makes sense to add them (e.g. SALES), and some facts are *not additive* (e.g. OUTSIDE_TEMPERATURE).
Dimensions are the data associated with the facts that give them meaning. These are things like times, locations, people, or object attributes (e.g. Project Status). These often (always?) come from [[Master Data]].
Typically there are many fewer rows in dimensions tables than there are in fact tables.
# Examples
- Mint Financial Data
- Facts - transaction amount
- Dimensions - vendor, account, date
- Phone
- Facts - number of calls made, data used
- Dimensions - phone numbers called, dates, account number
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## Source
- [Wikipedia](https://en.wikipedia.org/wiki/Data_warehouse)
## Related
- [[Star Schema]]