to
    the
        source

stop
       it

an abstract entity that associates an input to a corresponding output according to some rule

It
  is
   generally
    accepted
       that most,
        if not all,
          functions
             of the
            brain,
              such as
                  perception,
                     thought,
                     learning,
                        are a result of
                           its architecture
                             as a highly
                                connected
                                  network
                                       of neurons.