A VLAN (Virtual LAN) is used to logically segment a network without requiring physical separation. It enables grouping devices based on function or department regardless of their physical location. * Option A (DHCP): Assigns IP addresses dynamically but doesn't create network segments. * Option C (DNS): Resolves domain names to IP addresses, not used for network segmentation. * Option D (VPN): Provides secure remote access but does not relate to logical segmentation within a local network. CompTIA A+ Core 1 Exam Objective Reference: * Objective 2.3: Explain common logical networking concepts.