interaction vs interplay

interaction

noun

  • A conversation or exchange between people. 

  • The situation or occurrence in which two or more objects or events act upon one another to produce a new effect; the effect resulting from such a situation or occurrence. 

interplay

noun

  • Interaction; reciprocal relationship. 

verb

  • To interact. 

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