Understanding IPS and IDS: Using IPS and IDS. together for Defense in Depth. Over the past few years many papers and books have included articles explaining and supporting either. Intrusion Detection Systems (IDS) or the newer technology on the security block, Intrusion Prevention Systems. (IPS). Few have reviewed the value of implementing both IDS and IPS technologies. Most papers pit the. technologies against each other in a comparison or they show the evolution of IDS and the roadmap to IPS.