circuit board vs circuit card

circuit board and circuit card both are nouns.

Word	Noun	Adjective	Verb	Adverb
circuit board	Yes	No	No	No
circuit card	Yes	No	No	No

As nouns, circuit board and circuit card are synonyms defined as:

circuit board and circuit card: a printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities

Other synonyms of circuit board include add-in, board, card, plug-in.

circuit board (noun)	circuit card (noun)
a printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities	a printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities