The main elements of vCloud Director
The virtual data center (VDC) is the combination your cloud resources (virtual CPUs, memory, drive space, networks, and so on) that you can access within one account. This is an environment in which you create virtual machines, containers, networks and so on. You can increase its capacity as required by purchasing the necessary resources (CPUs, memory or drives).
vApp is a container that hosts virtual machines. You can create it empty or with virtual machines. Containers enable you to manage a group of virtual machines as one unit. This is especially useful if you manage a large virtual infrastructure. On the basis of vApp you can create templates. If you have the requirement to periodically create the same type of virtual machine groups, this vApp property will save you time. vCloud Director also enables you to create a separate vApp network, which means that additional insulation can be provided between two vApps. vApp can be used to group virtual machines belonging to the same business application.
Virtual machines (VMs) can be created from templates in the catalog (together with the OS) or from scratch, installing the required OS from an uploaded template or image.
Catalogs are folders in which you can store vApp templates, virtual machines and media files.
Org VDC Networks are the networks of your virtual data center, available by default for all vApps. Org VDC networks can be isolated (without access to the internet) and routed (with access to the internet).
In addition to Org VDC networks, which are available for all vApps, you can create vApp networks. On this network only virtual machines of this vApp will communicate: virtual machines from other vApps will not be accessible. The vApp network can be connected to the Org VDC network, thereby allowing this vApp to communicate with other vApps of the organization or external vApps.