Network segmentation is the foundation of modern security and management. Two primary techniques are used to divide a larger network into smaller, more manageable parts: VLANs and IP Subnetting.

VLANs (Virtual Local Area Networks)

VLANs operate at Layer 2 (Data Link Layer) of the OSI model. They group devices based on logical function rather than physical location. This means a user in accounting and a user in IT, both physically plugged into the same switch, can be logically separated into different VLANs.

• **Primary Benefit:** Broadcast Domain Isolation. A broadcast from one VLAN cannot be heard by another, reducing network chatter and improving security.
• **Implementation:** Configured on managed network switches.

IP Subnetting

Subnetting operates at Layer 3 (Network Layer). It is the practice of dividing an IP network into smaller sections by manipulating the subnet mask. All devices within the same subnet must have unique IP addresses.

• **Primary Benefit:** Efficient IP Address Allocation. It conserves addresses and provides structured routing paths.
• **Implementation:** Configured on routers and host machine IP settings.

**The Key Difference:** VLANs manage traffic and broadcast visibility within the same physical network hardware, while subnetting manages logical addressing and routing across different networks.