RJ-11 ( Registered Jack-11) a four- or six-wire connector primarily used to connect telephone equipment.
RJ-45 (Registered Jack-45) connector is an eight-wire connector that is commonly used to connect COMPUTERS to a LOCAL area network (LAN), PARTICULARLY Ethernet LANs.
AUI( Attachment Unit Interface.) is the part of the Ethernet standard that specifies how a Thicknet cable is to be CONNECTED to an Ethernet card. AUI specifies a coaxial cable connected to a transceiver that plugs into a 15-pin socket on the network interface card (NIC).
BNC stand for British Naval Connector (or Bayonet Nut Connector or Bayonet Neill Concelman)a type of connector used with coaxial cables such as RG-58.BNC connectors are used on both Thicknet and Thinnet.