Services available at vApp Networks and Org VDC Networks? (Info taken from VMware Documentation)

Org VDC Edge Services

Edge Gateways

An Edge Gateway provides a routed connection between an organization vDC network and an external network. It can provide any of the following services, defined in the GatewayFeatures element of the Edge Gateway's Configuration.

FirewallService	Specifies firewall rules that, when matched, block or allow incoming or outgoing network traffic.
GatewayDhcpService	Provides DHCP services to virtual machines on the network. A variant of this service, DhcpService, is intended to provide DHCP services in vApp networks.
GatewayIpsecVpnService	Defines one or more virtual private networks that connect an Edge Gateway to another network in or outside of the cloud.
LoadBalancerService	Distributes incoming requests across a set of servers.
NatService	Provides network address translation services to computers on the network.
StaticRoutingService	Specifies static routes to other networks

 vApp Edge Gateway Services

The  Features element defines features of the vApp network, and can include the following services:

DhcpService	Provides DHCP services to virtual machines on the network.
FirewallService	Specifies firewall rules that, when matched, block or allow incoming or outgoing network traffic.
NatService	Provides network address translation services to virtual machines on the network.
StaticRoutingService	Specifies static routes to other networks. Requires a routed organization vDC network.