在了解什麼是Opendaylight 計畫之前，要先了解幾個專有名詞 Software-Defined Networking (SDN)、Network functions Virtualization (NFV) 和 Network Virtualization (NV)，參考Which is Better – SDN or NFV 這篇文章：
SDN – separates the network’s control (brains) and forwarding (muscle) planes and provides a centralized view of the distributed network for more efficient orchestration and automation of network services.
NFV – focuses on optimizing the network services themselves. NFV decouples the network functions, such as DNS, Caching, etc., from proprietary hardware appliances, so they can run in software to accelerate service innovation and provisioning, particularly within service provider environments.
NV – ensures the network can integrate with and support the demands of virtualized architectures, particularly those with multi-tenancy requirements.