Local Area Network (LAN) communication can operate in two modes. Half-duplex and Full-duplex.
Half-duplex Local Area Network (LANs) are networks of the past. Half-duplex Local Area Networks (LAN) exists normally in a shared network medium like 10Base2 (coaxial cable), 10Base5 (coaxial cable), and Ethernet hubs. Devices operating in a half-duplex Local Area Network (LAN) cannot send and receive data simultaneously. A device can either Send data or Receive data only in a half-duplex Local Area Network (LAN). In half-duplex Local Area Networks (LANs), one device sends the frame and all other devices in the collision domain listen for the Ethernet frame. Collision is a problem in half duplex networks.
Almost all current networks operate in full-duplex mode. In a Local Area Network (LAN) operating in full-duplex mode, a device can send and receive Ethernet frames simultaneously. In a full-duplex mode, there are separate channels to send and receive Ethernet frames. There is no collision detection in devices operating in full-duplex mode, since collision detection is not required.