Jack plugs and sockets are widely found in audio and audio-video applications and are most commonly used for analogue audio signals. They are sometimes refered to as TRS connectors, which stands for Tip/Ring/Sleeve. The tip is the end of the plug, the ring is the middle section located between the two plastic dividers, and the sleeve is the rest of the metal part of the plug. Each part of the plug is electrically isolated from the others, allowing one plug to carry more than one signal.They are typically available as either mono (Single Channel, TR) versions, or Stereo (Dual Channel, TRS) varieties. However, three-channel versions (TRRS) are also available for when video signals are also needed.Types of Jack Connectors6.35 mm Jack ConnectorsAlso known as inch Jack Plugs and Sockets, these connectors are widely found on musical instruments, such as amplifiers and electric guitars or keyboards. Whether on the stage or in the studio, musicians and technicians will be very familiar with inch jack plugs. They are also sometimes known as phone connectors, due to their prevalence in connecting analogue phones and in commercial public address systems.3.5 mm Jack ConnectorsOften known as mini jack plugs or mini jack sockets, these 1/8 inch connectors are widely found in commercial and domestic hi-fi setups. Suitable for less demanding applications than their larger counterparts, mini-jacks are none-the-less used in a variety of specialist applications. They are also commonly found on headphone jacks in portable devices such as iPods or tablets.2.5mm Jack ConnectorsOften called as a sub-mini connector, this 3/32 inch connector functions in much the same was as a mini connector, but is optimised for smaller electronic devices.