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Essential Networking Terminology

networking osi model tcp/ip protocol ethernet

This page describes essential networking terms, covering concepts from OSI and TCP/IP models to specific protocols and hardware components.

Networking Terms

TermDescriptionReference
OSIOpen System Interconnection. A conceptual model that standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.
TCPIPTransmission Control Protocol/Internet Protocol. A suite of communication protocols used to interconnect network devices on the internet.
ARPAddress Resolution Protocol. Maps IP addresses to Ethernet (MAC) addresses. Used to find the MAC address associated with a given IP address on a local network.
RARPReverse Address Resolution Protocol. Maps Ethernet (MAC) addresses to IP addresses. (Note: largely superseded by BOOTP and DHCP).
RouterA networking device that forwards data packets between computer networks. Routers examine the destination IP address within the IP header of a packet to determine the optimal path for delivery.
HubConnects multiple Ethernet segments, acting as a central connection point. (Note: largely replaced by switches due to inefficiency).
SwitchSimilar to a router but operates with more intelligence at the data link layer (Layer 2). A switch forwards Ethernet packets to appropriate sub-networks based on MAC addresses.
EthernetA common networking technology for local area networks (LANs). It specifies cabling and signaling for the physical layer and data link layer. Commonly refers to Ethernet cables and related hardware.
GatewayA node (router) in a computer network that serves as an access point to another network. Connects two networks with different protocols.
MACMedium Access Control. A sublayer of the data link layer (Layer 2) in the OSI model. Handles segmentation, assembly, flow control, and error control (using ARQ protocols).
PHYPhysical Layer. Layer 1 of the OSI model. Deals with the physical aspects of the network, including modulation, syntax conversion, Forward Error Correction (FEC), and scrambling.
IP addressA logical address used to uniquely identify a device on an IP network (Internet or intranet). Can be either 32-bit (IPv4) or 128-bit (IPv6).
Ethernet addressThe physical address (MAC address) used to identify a device connected to an Ethernet network. It is a 48-bit address.
LANLocal Area Network. A network that connects computers and devices within a limited area, such as a home, school, or office building.
WANWide Area Network. A network that covers a broad area, such as a city, country, or the world.
InternetA global network of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide.
IoTInternet of Things. A network of physical objects (“things”) embedded with sensors, software, and other technologies for the purpose of connecting and exchanging data with other devices and systems over the Internet.
M2MMachine to Machine communication. Direct communication between devices using any type of network.