Common Connector Types | CompTIA A+ 220-1001 | 3.2

In this video you will learn about common connector types such as: RJ-11, RJ-45, RS-232, BNC, RG-59, RG-6, USB, Micro-USB, Mini-USB, USB-C, DB-9, Lightning, SCSI, eSATA, and Molex.


The RJ-11 is a telephone interface that uses a cable of twisted wire pairs and a modular jack with 2, 4, or 6 contacts. RJ-11 is the common connector for plugging a telephone into the wall and the handset into the telephone. RJ-11 is still a current connector standard.

RJ-11 Connector


The RJ-45 connector is an 8-pin connection used for Ethernet network adapters. The connector resembles the RJ-11 connector used with telephones in the United States. This connector most commonly connects to the end of a CAT 5 cable, which connects between a computer network card and a network device, such as a network router. RJ-45 is still a current connector standard.

RJ-45 Connector


The RS-232 connector is a form of serial data transmission used for connecting computers and its peripheral devices to allow serial data exchanges between them. The RS-232 connector is most commonly found in DB9 or DB15 connections on PCs for printers, mice, and modems. RS-232 connectors have mostly been replaced by USB cables. RS-232 is considered to be a connector that is in decline.

RS-232 Connector


The BNC (Bayonet Neill-Concelman) connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. After the BNC connector is inserted, it is turned, causing pins in the socket to be pinched into a locking groove on the plug. BNC is considered to be a legacy connector.

BNC Connector


The RG-59 connector is a specific type of coaxial cable connector often used for low-power video and RF signal connections and produces a characteristic impedance of 75 ohms. RG-59 is often used at baseband video frequencies, such as composite video. It may also be used for broadcast frequencies, but its high-frequency losses are too high to allow its use over long distances. RG-59 is typically used with CCTV. RG-59 is considered to be a current connector standard.

RG-59 Connector


The RG-6 connector is a common type of coaxial connector that is used in a variety of residential and commercial applications and also has a characteristic impedance of 75 ohms. RG-6 has a larger copper core than RG-59 which allows for more signal and bandwidth. RG-59 is commonly used for providing cable TV & internet providing by a cable provider. RG-6 is considered to be a current connector standard.

RG-6 Connector


Universal Serial Bus is an industry standard that establishes specifications for cables, connectors, and protocols for connection, communication and power supply between computers, peripherals and other computers. USB is considered to be a current connector standard.

USB Connector


Micro-USB is the smallest of the USB connector types used for connecting compact and mobile devices such as smartphones, MP3 players, GPS devices, photo printers, and digital cameras. Micro-USB is considered to be a current connector standard, but will eventually be displaced by the USB-C connector.

Micro-USB Connector


The mini-USB connector can be used with most digital cameras, external hard drives, USB hubs and other equipment. The mini-USB is much smaller than USB Type A & B but twice as thick as the micro-USB. Mini-USB is considered to be a legacy connector but it is still in use.

Mini-USB Connector


The USB-C connector is an industry-standard connector for transmitting both data and power on a single cable. The USB-C connector is easier to connect (reversible; no up or down side to the plug) and with the appropriate adapter allows backward compatibility to USB 2.0. USB-C is considered to be a current connector standard.

USB-C Connector


The DB9 connector is a 9-pin serial connector once common on PCs that was used for connecting peripherals like mice and keyboards. The DB9 connector can also be used for serial communications to networking equipment and be used with DB9 to USB adapters to connect to modern PCs without DB9 ports. DB9 is considered to be a legacy connector but is still utilized in special circumstances.

DB9 Connector


The Lightning connector is an 8-pin proprietary computer bus and power connector created and designed by Apple. The Lightning connector was introduced on Sept 12, 2012 to replace the 30-pin dock connector that was used to connect Apple mobile devices like iPhones, iPads, and iPods. The Lightning connector is considered to be a current connector standard.

Lightning Connector


The SCSI connector is used to connect computer parts that use a system called SCSI to communicate with each other. SCSI is used for connecting internal hard drives or external devices such as printers, storage, etc. SCSI is considered a legacy connector.

SCSI Connector


eSATA (external SATA) is a subset of the SATA (serial ATA) interface standard. The eSATA connector is used for connecting external storage devices to computers. eSATA cables are thicker than internal SATA cables. eSATA connectors are considered to be a current standard for connectors.

eSATA Connector


A molex connector is a 2-piece pin and socket interconnection that delivers power from a power supply to various drives and motherboard components inside of a PC. The molex connector is considered a legacy connector although it is still in use, but it has been replaced by SATA.

Molex Connector