Leading you to an educated decision.

Autonegotiation (ANeg)
Used by units that can handle different transmission rates such as 10 Mbit/s and 100 Mbit/s and different duplex modes. Each of the units then %u201Cdeclares%u201D its best technological modes of operation and then they will choose the best possible mode of operation that are shared by the two devices. The norm is the higher speed (100 Mbit/s) is preferred over lower speed (10 Mbit/s), and full duplex is preferred over half duplex at the same speed.