本标准定义了以太网局域网、接入网和城域网。以太网以选定的运行速度指定；并使用通用媒体访问控制（MAC）规范和管理信息库（MIB）。载波侦听多址冲突检测（CSMA/CD）MAC协议规定了共享介质（半双工）操作和全双工操作。特定于速度的媒体独立接口（MII）为选定的物理层实体（PHY）提供架构和可选的实现接口。物理层对用于传输的帧进行编码，并使用为操作速度、传输介质和支持的链路长度指定的调制对接收到的帧进行解码。其他指定功能包括:控制和管理协议，以及通过选定的双绞线PHY类型提供电源。

This standard defines Ethernet local area, access and metropolitan area networks. Ethernet is specified at selected speeds of operation; and uses a common media access control (MAC) specification and management information base (MIB). The Carrier Sense Multiple Access with Collision Detection (CSMA/CD) MAC protocol specifies shared medium (half duplex) operation, as well as full duplex operation. Speed specific Media Independent Interfaces (MIIs) provide an architectural and optional implementation interface to selected Physical Layer entities (PHY). The Physical Layer encodes frames for transmission and decodes received frames with the modulation specified for the speed of operation, transmission medium and supported link length. Other specified capabilities include: control and management protocols, and the provision of power over selected twisted pair PHY types.