Nouns are one of the nine parts of speech in the English language.
A noun is a person, place, thing, or idea. A simple test for a noun is adding the or a/an before the word. If it makes sense, then the word is a noun.
So, examples of nouns include stripper or whore (person), brothel or Storyville (place), cunt, twat, or pussy (thing), or (sexual) ecstasy (idea).
A proper noun is the name of a specific person, place, group, or event. All other nouns are common nouns.
The word stripper would be a common noun, but Candi or Bambi would be proper nouns (the names of specific strippers).