A tenant is a logical grouping of configuration. An administrator might belong to one or multiple tenants, but can only view and edit one tenant at a time. Each tenant has its own isolated control plane configuration.
Each tenant can optionally have its own isolated data plane. This will depend on the global configuration of the NSX Advanced Load Balancer deployment.
Tenants can be deployed within a Provider Context or a Tenant Context:
Provider Context mode: SE groups are shared across tenants
Tenant Context mode: SE groups are exclusive to each tenant
In NSX Advanced Load Balancer, Virtual Routing Forwarding (VRF) contexts can be created to isolate traffic within a system.