Internet Protocol Security - Definition from the Hotspot Shield Glossary
Also knowns as IPsec, this defines a set of protocols for network security at the packet layer of network communication. Previous security protocols were implemented at the application layer of the OSI reference model.
A main feature of IPsec is that security changes can be made to a whole network without having to make those changes on every individual device connected to that network. This improves the network management process. Many businesses include support for IPsec in their routers and a prominent supporter of the technology is Cisco. IPsec is extremely useful for the implementation of VPN's and for remote network access.