Optical vs Analog

What is optical audio other than another form of cord that uses light, and what makes it better than analog audio?

I am not an audio head but I imagine the difference is that optical will not suffer with RF interference over distance but at the far end the AMP/DAC will still have the same short comings if any.

Basically it cuts out the interference in the cables, but I am just guessing, sounds about right in my head.

Optical is technically digital. So look up digital vs analog for audio and you'll find your answer that way.

Its digital audio.. Where as it is traveled over a fiber optic cable.. It transmits the zeroes and ones via on and off light that blinks ultra fast... The zeroes and ones are then read and transfered to speakers which pulse the same way.. Speaks make sound by actuating and creating vibrations.. Essentially one is on.. 0 is off.. Its actually really simple when you think about it...
The optical fiber optic cable is completely resistant to EMR/EMI.. Allowing for a bit perfect audio stream and in turn depending on the source... Better audio.. Hope that helps

So in theory optical is better if there are a lot of other cords or distance?

Optical is better in general.