Glossary

CompTIA Network+ (N10-009) Glossary

By The Exam Atlas Editorial Team · Verified 2026-05-29

Plain-English definitions of the networking terms for Network+ study. Simplified for learning; CompTIA’s objectives are authoritative.

TermDefinition
OSI modelA seven-layer model describing how networks communicate.
ProtocolAgreed rules for how devices exchange data.
IP addressA numeric address identifying a device on a network.
SubnetA logical division of an IP network.
Subnet maskDefines the network vs host portion of an IP.
Default gatewayThe router used to reach other networks.
DNSResolves names to IP addresses.
DHCPAutomatically assigns IP addresses.
NATTranslates private addresses to public ones.
VLANA logical segment of a switched network.
SwitchForwards frames within a local network.
RouterForwards packets between networks.
FirewallFilters traffic based on rules.
LatencyThe delay before data transfer begins.
BandwidthThe maximum data rate of a link.
ThroughputThe actual data rate achieved.
TopologyThe arrangement of a network (star, mesh, etc.).
Wireless standardWi-Fi generations (e.g., 802.11ax).
PoEPower over Ethernet — power and data on one cable.
SNMPA protocol for monitoring network devices.
QoSQuality of Service — prioritising certain traffic.

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