Top down view of a Lightning cable, showing the eight-pin connector
|Type||Data and power connector|
|Superseded||30-pin dock connector|
|Pin 2||L0p||lane 0 positive|
|Pin 3||L0n||lane 0 negative|
|Pin 4||ID0||identification/control 0|
|Pin 5||PWR||power (charger or battery)|
|Pin 6||L1n||lane 1 negative|
|Pin 7||L1p||lane 1 positive|
|Pin 8||ID1||identification/control 1|
|Two differential pair lanes (L0p/n and L1p/n) may swap in IC of device connector (lanes don't swap if accessory identification chip connect to ID0 pin)|
Lightning is a proprietary computer bus and power connector created by Apple Inc. to replace its previous proprietary 30-pin dock connector, used to connect Apple mobile devices like iPhones, iPads and iPods to host computers, external monitors, cameras, USB battery chargers and other peripherals. Using eight pins instead of thirty, Lightning is significantly more compact than the 30-pin dock connector and can be inserted with either side facing up. However, it is incompatible with cables and peripherals designed for its predecessor, unless used with an adapter. It was introduced in 2012 and as of November 2014 is used by all Apple mobile devices.
The Lightning connector was introduced on September 12, 2012  as a replacement for the 30-pin dock connector for all new hardware that was announced at the same event. The first compatible devices were the iPhone 5, iPod Touch (5th generation), and the iPod Nano (7th generation). The iPad (4th generation) and the iPad Mini (1st generation) were added as Lightning devices in October 2012. On September 20, 2013 Apple released the iPhone 5C and iPhone 5S. On October 22, 2013, Apple released the iPad Mini with Retina Display and the iPad Air. On September 19, 2014 Apple released the iPhone 6 and the iPhone 6 Plus.
Lightning is an eight-pin connector which carries a digital signal. It is non-directional and can be inserted into the device with either side facing up or down. Apple offers various adapters between the Lightning and other interfaces such as Lightning to Apple proprietary 30 pin, Lightning to universal serial bus (USB) as well as accessories to interface with high-definition televisions, VGA monitors, Secure Digital (SD) cards and SD card reader. The Lightning to 30-pin adapter supports only a limited subset of the available 30 pin signals: USB data, USB charging, and analog audio output. Official Lightning connectors contain an authentication chip that makes it difficult for third-party manufacturers to produce compatible accessories without being approved by Apple.
Comparisons with Micro-USB
Apple has not publicly discussed micro-USB, but industry observers believe Lightning was used for the following advantages:
- Accessibility The ability of a Lightning plug to be inserted in either direction reduces wear from attempts to insert the plug upside down, and offers user convenience.
- Bidirectionality The Lightning port can either charge a device, or allow the device to power accessories. The optional supplement USB On-The-Go allows USB devices to do this.
- Flexibility The Lightning port can reassign lanes from digital to analog allowing, for example, analogue audio to be available from the iPhone dock.
In December, 2013, the USB 3.0 Promoter Group announced a new USB Type-C specification, "expected to be published by the middle of 2014" As listed by the Promoter Group, the key characteristics of USB Type-C are similar to many Lightning features, including power capacity and reversibility. 
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|Wikimedia Commons has media related to Apple Lightning.|
- Wingfield, Nick & Chen, Brian X. (May 5, 2013). "Accessories No Longer Tethered to Apple". The New York Times.