What is this cord for?

In the box of my Macbook there was a another cord besides the charge plug. What is this for?

I can't figure out for the life of me what it is for.

i think your talking about a mini dvi converter?

It's an extension cord. The part of the charger brick that plugs into the wall can pop off and you can use the longer cable if necessary

trpnmonkey41 is probably right sorry for being wrong.

the charger cords can be interchanged, don't be afraid to tug that little square on the corner of the ac unit

Yes, pull the "perforated" part of the plug UP! It will slide out and you can connect the longer piece. I never use the smaller one anymore..I find it's long enough to accomodate you whenever, and it's short enough to not be annoying to keep it on all the time!

Oh great... I thought it was an extension cord... but I was too anxious to plug it in initially. So i just disregarded the extension cable. Thanks... I guess Im learning new stuff already