RJ11 Ethernet plug is mainly used to connect modem.
The name RJ stands for registered jack. RJ11 Is derived from the Bell system code(Universal Service Ordering Codes). Used to connect the user's device to the public network
Formerly known as WExW, where x means ‘activity’, contacts or needles. For example, WE6W has all 6 contacts, numbered 1 to 6, and the WE4W interface uses only 4 pins and the outermost two contacts (1 and 6).WExW，WE2W only uses the middle two stitches. RJ11 usually refers to a 6-pin connection device, but it can also refer to a 4-pin connection device