bookshelf vs library

bookshelf

noun
  • A shelf or shelves for storing books for easy visual reference. 

library

noun
  • A room dedicated to storing books. 

  • An institution which holds books and/or other forms of media for use by the public or qualified people often lending them out, as well as providing various other services for its users. 

  • An equivalent collection of analogous information in a non-printed form, e.g. record library. 

  • A collection of DNA material from a single organism or relative to a single disease. 

  • The deck or draw pile. 

  • Any institution that lends out its goods for use by the public or a community. 

  • A collection of software routines that provide functionality to be incorporated into or used by a computer program. 

  • A collection of books or other forms of stored information. 

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