handover vs retention

handover

noun
  • the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. 

  • The transference of authority, control, power or knowledge from one agency to another, or from one state to another. 

  • The transfer of goods from the dealer to the purchaser, often of illegal goods. 

  • the process of transferring satellite control responsibility from one earth station to another without loss or interruption of service. 

  • The information passed on in such a case. 

retention

noun
  • The portion of a potential damange that must be paid for by the holder of an insurance policy. 

  • The act or power of remembering things 

  • The involuntary withholding of urine and faeces 

  • A memory; what is retained in the mind 

  • The length of time an individual remains in treatment 

  • The right to withhold a debt, or of retaining property until a debt due to the person claiming the right is duly paid; a lien. 

  • The act of retaining or something retained 

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