There is a authentication chip inside each lightning connector to tells your Apple device that the cable is Apple MFI Certified. This is important because a non-certified lightning cables could be very dangerous to your device due to unstable current, voltage, and may be not good performance on data transfer speed and charging speed. (You may have noticed a warning message on your phone when a non-MFI cable was detected.)
1 m/3-foot : 24AWG tinned copper wire.
1-2m/3-foot to 6-foot: 22AWG tinned copper wire.
3m/10-foot: 18AWG tinned copper wire.