explorer vs viewport

explorer

noun
  • A visual representation of a file system etc. through which the user can navigate. 

  • One who explores something 

  • A person who by means of travel (notably an expedition) searches out new information. 

  • Any of various hand tools, with sharp points, used in dentistry. 

viewport

noun
  • A viewing window. 

  • A typically rectangular region representing the range or area currently visible (within a window, screen, etc.). 

verb
  • To clip (an image or region) so that it fits in a viewport. 

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