VLAN(Virtual Local Area Network) is a logical grouping of network users and resources connected to administratively defined ports on a switch. VLAN's break up broadcast domains in layer 2 switch network.Virtual LANs (VLANs) divide one physical network into multiple broadcast domains. But, VLAN-enabled switches cannot by themselves, forward traffic across VLAN boundaries. So you need to have routing between these VLANs which is called interVLAN routing. You can achieve this by using either a Layer 3 switch or a router.