caterer vs seller

caterer

noun
  • A person employed to obtain and maintain the storage of provisions, especially food. 

  • A person or company hired to provide and serve food, usually for a large group and at a location separate from where the food is prepared. 

seller

noun
  • Someone who sells; a vendor; a clerk. 

  • Something which sells. 

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