plicitly.
</li></ul><p>Applications providing a job are generically called providers, 
  applications requesting a job are called consumers.
  Providers, hence, are servers, workers and publishers, and
  consumers are clients, pushers and subscribers.
  Note that this is somewhat different from the 
  data-centric terminology &quot;producer&quot; and &quot;consumer&quot;.
  It is not very useful
  to distinugish servers from clients or
  pushers from workers by referring to the distinction
  of producing or