personal identification number vs PIN number

personal identification number and PIN number both are nouns.

Word	Noun	Adjective	Verb	Adverb
personal identification number	Yes	No	No	No
PIN number	Yes	No	No	No

As nouns, personal identification number and PIN number are synonyms defined as:

personal identification number and PIN number: a number you choose and use to gain access to various accounts

Other synonyms of personal identification number include PIN.

personal identification number (noun)	PIN number (noun)
a number you choose and use to gain access to various accounts	a number you choose and use to gain access to various accounts