New Connection Cable in iPhone 5 called Lightning Cable , also Apple uses this cable at iPod touch, iPod nano , iPad Mini and iPad 4 . Regarding old connectors its smaller than the others. For old accesories to use it together it requires adaptor .
Why Apple Uses Lightning Cable
Very Small: Lightning has 8 pins only. Old connectors has 30 pins that makes Lightning very small. That means Apple can manufacture more thin products like iPhone 5.
Chip: Apple Lightning Cable has its own chip .By using this chip it can determine its plugged direction . So that means for a while you have to use original cables.
Its not fast as Thunderbolt : Lightning is based USB2.0 becouse of this it can not offer a high performance such as USB 3.0 or Thunderbolt cables. Apple promises for convertor adaptor for HDMI and VGA.
Adaptors very Expensive: There are few types of adaptor prices between 25 usd and 50 usd . Its i little bit waste of money ..