A ______ is a network inside a network.

• A. VLAN
• B. Subnet
• C. Broadcast domain
• D. Collision domain

Answer: (B)

Subnetting divides a larger IP network into smaller pieces by applying a subnet mask. Each subnet functions as its own logical network with a distinct address range, so you can manage and route traffic more efficiently within a bigger network. This is why it’s described as a network inside a network: multiple subnets exist within the single overarching IP space, each isolated for addressing and routing purposes. Routers connect these subnets and transfer traffic between them, while devices within the same subnet can communicate directly. Other concepts describe different kinds of separation: a VLAN creates separate broadcast domains at Layer 2, a broadcast domain is all devices that receive the same broadcast, and a collision domain is the shared segment where collisions can occur.