RJ11 is a type of connector that is used for telephone lines. RJ11 has four copper wires that carry analog voice signals. RJ11 is smaller than RJ45, which is used for Ethernet cables. RJ11 is also different from VGA and USB, which are used for video and data transmission respectively. Reference: The Official CompTIA IT Fundamentals (ITF+) Student Guide (Exam FC0-U61), Chapter 4, Section 4.2, Page 166.