Is normalisation done on the primary key or on the candidate keys?

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Im not sure about the correct definitions for normalisations, as primary key and candidate key are used interchangeably. I have come across these 2 definitions when trying to find a definition for 2NF and 3NF.

Definitions 1:

2NF: "And every non-prime attribute of the table is either dependent on the whole of a candidate key, or on another non-prime attribute."

3NF: "No candidate key transitively determines any non-prime attribute."

Definitions 2:

2NF: "No non-key attributes should functionally depend on part of the primary key"

3NF : "There is no transitive dependancy of a non-key attribute on the primary key"

I am unsure as there is sometimes multiple keys in a relations.

So my question is: say I have been given a database with multiple candidate keys , do I look at the functional dependancies between ALL the candidate keys and non prime attributes or ONLY the primary key that we have chosen?

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