Advantages of such splitting are primarily for boosting performance and improving security.
When a cyber-criminal gains unauthorized access to a network, segmentation or “zoning” can provide effective controls to limit further movement across the network.
[3] PCI-DSS (Payment Card Industry Data Security Standard), and similar standards, provide guidance on creating clear separation of data within the network, for example separating the network for Payment Card authorizations from those for Point-of-Service (till) or customer Wi-Fi traffic.
[4] Finance and Human Resources typically need access via their own VLAN to their application servers because of the confidential nature of the information they process and store.
[6][7] Segregation is typically achieved by a combination of firewalls and VLANs (virtual local area networks).