What is network segmentation and what is a VLAN?

Network segmentation divides a network into smaller isolated subnetworks to contain breaches, reduce attack surface, and improve performance. A Virtual Local Area Network, or VLAN, is a logical grouping of network devices that communicate as if they were on the same physical network regardless of their physical location. VLANs are created on managed switches and separate broadcast domains. Traffic between VLANs must pass through a router or layer-3 switch with access control rules.