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A small networking glossary

Plain-language definitions to keep beside your reading.

Learning notes · Updated September 26, 2026

Connection terms

ISP: an internet service provider, the organization supplying internet access.

LAN: a local area network, such as the devices connected within a home.

Ethernet: a family of networking technologies commonly used for wired local connections.

Wi-Fi: wireless networking technology used to connect nearby devices.

Equipment terms

Modem: equipment used with certain access technologies to connect to provider service.

Router: a device that directs traffic between networks.

Access point: equipment that provides a wireless connection to a local network.

Gateway: a term with several networking meanings; in home cable internet, it commonly refers to combined modem/router equipment.

Measurement terms

Mbps: megabits per second, a data transfer rate.

Bandwidth: available capacity for transferring data.

Throughput: the data transfer rate actually achieved.

Latency: delay in communication, commonly measured in milliseconds.

Names and addresses

SSID: the name used to identify a Wi-Fi network.

IP address: an address used to identify an interface for network communication.

DNS: the system that helps translate domain names into network addresses.

These definitions are simplified for beginners. A term may have a more specific meaning in a product manual or engineering document.

More terms you may encounter

Packet: a unit of data sent across a network. A larger communication is commonly carried in many packets.

Upload: sending data from your device to another system.

Download: receiving data from another system onto your device.

Jitter: variation in communication delay.

Packet loss: the failure of some transmitted packets to arrive at their destination.

WAN: a wide area network; on a home router, the label commonly identifies the upstream connection.

GHz: gigahertz, a frequency unit. Wi-Fi band labels use frequency, not file transfer rate.

MB: megabytes, a data-size unit; capitalization distinguishes it from megabits in common usage.

Mesh network: in home Wi-Fi, a system of coordinated devices used to provide wireless coverage across an area.

Read terms together

“100 Mbps download” describes a transfer rate in one direction. “5 GHz Wi-Fi” describes a wireless frequency band. These figures measure different properties and should not be compared as if they were the same kind of number.