We can find 3 types of jack connector, monaural TS connector (tip-sleeve), TRS (tip-ring-sleeve) and TRRS stereo plug (tip-ring-ring-sleeve) which is used in most mobile devices, tablets, MP3 etc ...
We can difference these 3 types of connectors according to their diameter:

1. 6.35 mm jack connector or TS.
2. 3.5mm minijack connector or TRS, is the most common, usually used in headphone's output of portable devices.
3. 2.5mm jack connector or TRRS.

It consists of a maximum of three connecting parts being called the largest mass or negative polarity and two smaller size located more towards the end of the connector,
The called positive that correspond to each channel, such three-part plug can transmit signals in two separate channels, also known as stereo signals. There's a mono version, consisting of only two parts, a negative and a positive.

A. Protector
B. Stem
C. Ring
D. Tip
E. Kindred
F. Ring (Signal Right)
G. Tip (Signal Left)

It is another type of connector name Jack. You can also call TRRS or TS connector. To differentiate only have to look at the number of rings that has the connector. There Jack connectors of various diameters: The original, one-quarter (6.35 mm) and the miniature 3.5 mm (about one-eighth) and 2.5 mm (about 3/32.). The most used are 3.5 mm are used in portable devices such as mp3, for the headphone output. The least 2.5 mm is used, but is also used in small devices. On the PC we find that the jack have different colors, we put a small list to differentiate. Green TRS 3.5 mm audio output, front channels Black TRS 3.5 mm audio output, Grey rear channels TRS 3.5 mm audio output, side channels Orange 3.5 mm TRS dual outlet center ysBlue ubwoofer TRS 3.5mm audio input, line level Rosa/Red TS 3.5 mm microphone input mono/stereo

The XLR or Cannon is a type of connector that usually connect balanced lines. In fact, it is more balanced connector used for professional audio applications, and is also the standard connector used in entertainment lighting equipment to transmit the digital control signal "DMX". His nickname cannon, for which he is best known in Spain is that the first to be used in this country, were made by theITT/CANNON brand, and carried "cannon" stamped on the chassis. It has three pin plug and European standard for audio signals is as follows: for the earth or mesh. for one-phase signal, known as a living or hot to the back or push-pull signal, known as return or cold. It is available in version 3-pin and 5-pin.