columnist vs correspondent

columnist

noun
  • A regular writer of a column, such as in a magazine or newspaper 

correspondent

noun
  • Someone who communicates with another person, or a publication, by writing. 

  • Someone who or something which corresponds. 

  • A journalist who sends reports back to a newspaper or radio or television station from a distant or overseas location. 

adj
  • Corresponding; suitable; adapted; congruous. 

  • Conforming; obedient. 

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