{HEAD ~ An “execution server}” manages {TAIL ~ requests} from client machines based on priorities assigned to the requests 
{ HEAD ~ An “ execution server } ” manages { TAIL ~ requests } from client machines based on priorities assigned to the requests
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH