BNC interface refers to the coaxial cable interface for 75 Euro coaxial cable connection to provide receiver (RX) and sender (TX) channels, which is used for unbalanced signal connection.
The fiber interface is the physical interface used to connect the fiber optical cable. There are usually SC, ST, LC, FC and other types. For a 10Base-F connection, the connector is usually of type ST and the other end is a fiber walker. FC is the abbreviation of Ferrule Connector. Its external reinforcement uses metal sets with the screw buckle for fastening. The ST interface is typically used for 10Base-F, and the SC interface is typically used for 100Base-FX and GBIC, and LC is typically used for SFP.
RJ-45 interface is the most commonly used interface in Ethernet. RJ-45, a common name, refers to the IEC (60) 603-7 standardization which uses the definite the modular jack or plug with eight locations (8-pin) in international connector standard.
RS-232-C interface (also known as EIA RS-232-C) is the most commonly used serial communication interface. It was developed in 1970 by the American Electronics Industry Association (EIA) joint Bell system, modem manufacturers and computer terminal manufacturers to develop a standard for serial communication. Its full name is “The serial binary data exchange interface technology standards between Data Terminal Equipment (DTE) and Data Communication Equipment (DCE)." The standard specifies a 25-pin DB25 connector, the signal content of each pin of the connector and also specifies the level of the various signals.
RJ-11 interface is what we usually call the telephone line interface. RJ-11 is a generic name for connectors developed by Western Electric. Its shape is defined as a 6-pin connector. It is formerly known as WExW, where x means "active", contact or thread. For example, WE6W has all six contacts, numbered 1 to 6. WE4W interface only uses 4-pin, the outermost two contacts (1 and 6) do not use but only use the middle two-pin (that is, for telephone line interface).