concept vs idea

concept

noun
  • Understanding retained in the mind, from experience, reasoning and imagination; a generalization (generic, basic form), or abstraction (mental impression), of a particular set of instances or occurrences (specific, though different, recorded manifestations of the concept). 

  • An abstract and general idea; an abstraction. 

  • A description of supported operations on a type, including their syntax and semantics. 

verb
  • to conceive; to dream up 

idea

noun
  • More generally, any result of mental activity; a thought, a notion; a way of thinking. 

  • An abstract archetype of a given thing, compared to which real-life examples are seen as imperfect approximations; pure essence, as opposed to actual examples. 

  • A conception in the mind of something to be done; a plan for doing something, an intention. 

  • A purposeful aim or goal; intent 

  • A musical theme or melodic subject. 

  • An image of an object that is formed in the mind or recalled by the memory. 

  • A vague or fanciful notion; a feeling or hunch; an impression. 

How often have the words concept and idea occurred in a corpus of books? (source: Google Ngram Viewer )