Ethernet Connectors

Short for Registered Jack-RJ-45, an eight-wire connector
used commonly to connect onto a local-area networks (LAN), especially Ethernets. RJ-45 connectors look similar to the ubiquitous RJ-11 connectors used for connecting telephone equipment and they are somewhat thinner.

Although used for a variety of purposes, the RJ-45 connector is probably most commonly used for 10Base-T and 100Base-TX Ethernet connections.  Because only two pairs of wires in the eight-pin RJ-45 connector are used to carry Ethernet signals, and both 10BASE-T and 100BASE-TX use the same pins, a crossover cable made for one will also
work with the other.

The BNC connector is used for RF signal connections, for analog and serial digital interface video signals, amateur radio antenna connections, aviation electronics (avionics) and many other types of electronic test equipment. It is an alternative to the RCA connector when used for composite video on commercial video devices, although many consumer electronics devices with RCA jacks can be used with BNC-only commercial video equipment via a simple adapter. BNC connectors were commonly used on 10base2 thin Ethernet networks, both on cable interconnections and network cards. 

Optical Fiber Connectors

802.8 is the IEEE standard for fiber optic cables.

An optical fiber connector terminates the end of an optical fiber, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so that light can pass. Most optical fiber connectors are spring-loaded: The fiber end faces of the two connectors are pressed together, resulting in a direct glass to glass or plastic to plastic contact.

A variety of optical fiber connectors are available. The main differences among types of connectors are dimensions and methods of mechanical coupling. Generally, organizations will standardize on one kind of connector, depending on what equipment they commonly use, or per type of fiber (one for multimode, one for single mode). In datacom and telecom applications nowadays small form factor connectors (e.g. LC) and multi-fiber connectors (e.g. MTP) are replacing the traditional connectors (e.g. SC), mainly to pack more connectors on the overcrowded faceplate.

  LC connectors are replacing SC connectors in corporate networking environments due to their smaller size; they are often found on small form-factor pluggable transceivers.  LC is a new connector that uses a 1.25 mm ferrule, half the size of the ST. Otherwise, it's a standard ceramic ferrule connector, easily terminated with any adhesive. Good performance, highly favored for single mode.

SC is a snap-in connector that is widely used in single mode systems for it's excellent performance. It's a snap-in connector that latches with a simple push-pull motion. It is also available in a duplex configuration. SC connectors offer excellent packing density, and their push-pull design reduces the chance of fiber end face contact damage during connection; frequently found on the previous generation of corporate networking gear, using GBICs.

  ST (an AT&T Trademark) is the most popular connector for multimode networks, like most buildings and campuses. It has a bayonet mount and a long cylindrical ferrule to hold the fiber. Most ferrules are ceramic, but some are metal or plastic. And because they are spring-loaded, you have to make sure they are seated properly. If you have high loss, reconnect them to see if it makes a difference.

  MT-RJ (Mechanical Transfer Registered Jack) uses a form factor and latch similar to the RJ-45 connectors. It is easier to terminate and install than ST or SC connectors. The smaller size allows twice the port density on a face plate than ST or SC connectors do. The MT-RJ connector was designed by AMP, but was later standardized as FOCIS 12 (Fiber Optic Connector Intermateability Standards) in EIA/TIA-604-12. There are two variations: pinned and no-pin. The pinned variety, which has two small stainless steel guide pins on the face of the connector, is used in patch panels to mate with the no-pin connectors on MT-RJ patch cords.

Computer Connectors

4 Pin Berg Connector
Used to connect the PSU to small form factor devices, such as 3.5" floppy drives.
available in: AT, ATX & ATX-2

  4 Pin Molex Connector
This is used to power various components, including hard drives and optical drives.
available in:

20 Pin Molex ATX Power Connector
This is used to power the system board in ATX systems.
available in: ATX( ATX-2 have four extra pins)

  4 Pin Molex P4 12V Power Connector
Used specifically for Pentium 4 Processor system boards.
available in: ATX (integrated into the power connector in ATX-2)

  6 Pin AUX Connector
Provides +5V DC, and two connections of +3.3V.
available in:

The 4-pin Berg connectors used to connect floppy disk drive units to the power supply unit, Certain Molex connectors are used for providing power to the motherboard, fans, and floppy disk drives; and hundreds of others.

the 2-pin Berg connectors used as jumpers for motherboard configuration.

Sound, video, USB 1.1, USB 2.0, serial, IEEE 1394 / Firewire, parallel, NIC, modem, PS/2)

Keyboard PS/2 connectors are purple.   Mouse Green, keyboard purple

Note that some manufacturers, most notably Compaq and Dell, have produced power supplies using the same connectors as ATX but with different voltages on different pins; mismatching such PSUs and motherboards can result in damage to either or both.

4 Pin Berg Connector
Used to connect the PSU to small form factor devices, such as 3.5" floppy drives.
available in: AT, ATX & ATX-2

USB stands for Universal Serial Bus which is an standard and specifications for cables, connectors and protocols for these connections.

Besides carrying information USB is also capable of carrying low voltage power.

While USB 2 and USB 3 look almost identical, USB 2.0 can transfer data at 480 megabits per second (mbps) which is 60 megabytes per second (MBps). USB 3.0 can transfer data at up to 5gbps(640MBps) which is over 10 times faster than USB 2.0

The image below shows you the different types of USB connectors.

HDMI stands for High Definition Multimedia Interface. HDMI cables carry both audio and video signals in the same cables and connectors and are rated for 720p and 1080i signals.