Intrusion Prevention Systems (IPS)
Software that prevents an attack on a network or computer system. An IPS is a significant step beyond an IDS (intrusion detection system), because it stops the attack from damaging or retrieving data. Whereas an IDS passively monitors traffic by sniffing packets off of a switch port, an IPS resides inline like a firewall, intercepting and forwarding packets. It can thus block attacks in real time.