Tacker mainly consists of two resources:
Network Functions Virtualisation Orchestrator (NFVO)
Virtualised Network Function Manager (VNFM)
NFVO is functional block that manages the Network Service (NS) lifecycle and coordinates the management of NS lifecycle, VNF lifecycle (supported by the VNFM) and NFVI resources (supported by the VIM) to ensure an optimized allocation of the necessary resources and connectivity.
VNFM is functional block that is responsible for the lifecycle management of VNF.