"A stand-alone packet sniffer doesn't transmit any packets, but when installed non-standalone on a normal computer, the sniffing program will often generate traffic. For example, it might send out DNS reverse lookups in order to find names associated with IP addresses."

from http://www.robertgraham.com/pubs/sniffing-faq.html -- sention 2.5..
what does it meant by stand-alone packet sniffer and non-standalone one?