The document provides an introduction to Software Defined Networking (SDN), emphasizing its framework aimed at enhancing network administration through separation of control and data planes, centralization, and programmability. It discusses alternative APIs, the significance of SDN in virtualization and orchestration, and the evolution of SDN definitions along with key functionalities that address network management and performance. Additionally, the document highlights various protocols and technologies, such as OpenFlow and XMPP, that support SDN implementation and management.