VMware ESXi is a bare-metal hypervisor software installed on servers that can use the physical hardware to create one or more virtual machines (VMs). It is an operating system-independent hypervisor based on the VMkernal operating system that interfaces with agents that run on top of it. ESXi stands for Elastic Sky X Integrated.
A local area network (LAN) is a group of computers connected via physical networking hardware, typically a switch. A virtual local area network (VLAN) divides a LAN into isolated segments, reducing network broadcast congestion. A VLAN can also span multiple networks, linking networked computers across physical locations (different switches).