Each data packet is assigned the IP address of the sender and the IP address of the recipient. The term network refers to the part of the IP address that identifies each network. The terms host and node refer to the parts of the IP address that identify a specific machine on a network.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 87.