Virtualisation
Cisco Packet Tracer is a network simulation tool that allows IT professionals to design and experiment with network behavior using a virtualized environment. It offers the ability to simulate the configuration of Cisco routers and switches using a drag-and-drop interface. While it does provide a high level of simulation, it is not a 1:1 replacement for real hardware or a full virtualization solution like VMware or Hyper-V.
Packet Tracer focuses on the networking stack, up to the application layer, and allows for the emulation of a range of networking protocols. This enables professionals to simulate different networking conditions and configurations for educational or testing purposes.
In summary, Cisco Packet Tracer does constitute a form of network virtualization but is more accurately described as a simulator. It abstracts the underlying hardware into a software interface but lacks some of the more complex, real-world attributes and behaviors you would expect in a full-scale, production network.