Which Cisco Nexus 1000V component is the equivalent of a line card on a standard Cisco Nexus switch?

The Virtual Ethernet Module (VEM) resides in the hypervisor kernel on each host and provides data plane functionality, acting as the distributed virtual switch that processes network traffic for virtual machines, just like a line card handles port traffic on a physical switch.

The Virtual Supervisor Module (VSM) is the control plane for the Cisco Nexus 1000V, managing and configuring all VEMs, making it analogous to the supervisor engine, not a line card.

A Virtual Service Blade (VSB) is a general term for a virtual appliance that can run services within a virtualized environment, not a direct component of the Nexus 1000V's core switching architecture.

The Virtual Security Gateway (VSG) is a specialized security appliance that provides firewalling and security services for virtual machines, distinct from the core switching function of a line card.