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# About relational databases
## What is a relation?
A common misconception is that the "relations" in a relational database are about relations between database tables.
Actually, the relations in a relational database are the tables.
A relation "relates" a set of values with another set of values.
For example, a relation can relate the name of a person with their birth date and birth place. For example:
(person name) => (birth date, birth place)
(Alice) => (1979-12-03, Barcelona)
(Bob) => (1995-03-04, Paris)
...
Many computer languages have similar concepts:
* Python mapping types such as dict
* C++ std::map
* Java java.util.Map
* C# System.Collections.Generic.Dictionary
* Javascript Object
* PHP arrays
Relations are a natural concept, so although non-relational data systems exist, most data can be stored as relations.
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