Developed in the 70s independently. The IEEE standardised a protocol with the 802 committee. Ethernet transmits data in frames, each frame contains the address of the sender and the recipient MAC address which relates to the NIC card of the physical device, a 48bit number, usually expressed in hexadecimal.
standard/traditional/fast/gigabit/10gigabit/100gigabit
CSMACD was used to detect line silence and then potential collision with radio block, for subsequent retransmission. Uses any topology.
Most modern system uses a switch to join devices which means collisions are impossible as a fullduplex singular link for each device is provided.
Where ethernet is used in the datalink layer then there are two sub-layers: