ISO standards along with VLAN

VLAN is also known as Virtual LAN or Virtual Local Area Network. A Virtual Local Area Network is a single layer-2 network that can be divided into multiple different broadcast domains that are equally isolated so that packets can only pass between them through one or more routers. VLANs are setup by network architects to give the division services which are normally offered only by routers in LAN configurations.
Routers in VLAN topologies give security, broadcast filtering, traffic flow management, and address summarization. And also, switches may not be able to bridge or connect IP traffic between VLANs because it will breach the reliability of the VLAN broadcast domain. IEEE 802.1Q is the most commonly used protocol today in configuring VLANs.