handshakes

/HH AE1 N D SH EY0 K S/
noun
  1. 1

    The grasping of hands by two people when greeting, leave-taking, or making an agreement.

  2. 2

    An exchange of signals between two devices when communications begin in order to ensure synchronization.

Source: https://en.wiktionary.org/wiki/handshake, https://en.wiktionary.org/wiki/handshakes