RJ-11 connectors are somewhat similar to RJ-45 connectors, which are discussed next, though they are a little smaller. Both RJ-11 and RJ-45 connectors have small plastic flange on top of the connector to ensure a secure connection. Figure 5 shows two views of an RJ-11 connector.
Figure 5 RJ-11 connectors.RJ-45 Connectors
RJ-45 connectors are the ones you are most likely going to encounter in your network travels. RJ-45 connectors are used with twisted-pair cabling, the most prevalent network cable in use today. RJ-45 connectors resemble the aforementioned RJ-11 phone jacks, but support up to eight wires instead of the six supported by RJ-11 connectors. RJ-45 connectors are also larger. Figure 6 shows the RJ-45 connectors.
Figure 6 RJ-45 connectors.