The logical switching capability in the NSX Edge platform provides the ability to spin up isolated logical L2 networks with the same flexibility and agility that exists for virtual machines.
A cloud deployment for a virtual data center has a variety of applications across multiple tenants. These applications and tenants require isolation from each other for security, fault isolation, and to avoid overlapping IP addressing issues. Endpoints, both virtual and physical, can connect to logical segments and establish connectivity independently from their physical location in the data center network. This is enabled through the decoupling of network infrastructure from logical network (i.e., underlay network from overlay network) provided by NSX-T network virtualization.
A logical switch provides a representation of Layer 2 switched connectivity across many hosts with Layer 3 IP reachability between them. If you plan to restrict some logical networks to a limited set of hosts or you have custom connectivity requirements, you may find it necessary to create additional logical switches.