relay vs swap out

relay

verb
  • To pass on or transfer (information). 

noun
  • A track and field discipline where runners take turns in carrying a baton from start to finish. Most common events are 4x100 meter and 4x400 meter competitions. 

  • An electrical actuator that allows a relatively small electrical voltage or current to control a larger voltage or current. 

  • A series of vehicles travelling in sequence. 

  • A new set of horses kept along a specific route so that they can replace animals that are tired. 

  • A new set of hounds. 

  • A new set of anything. 

swap out

verb
  • To exchange (something or someone) for an unused (or less-used) equivalent. 

  • To exchange (something) for (something else). (usually followed by with or for) 

  • To transfer (memory contents) into a swap file. 

noun
  • Anything that is swapped out for another; an exchange. 

  • A pre-prepared food item used in place of an unfinished food item in order to cut down the overall preparation time during filming. 

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