Battery Cables

I recently replaced the battery on my 1998 Concorde. The Positive terminal was badly corroded so I had to replace it. There are two cables. I Know one is the battery cable. What is the smaller cable for?

I recently replaced the battery on my 1998 Concorde. The Positive terminal was badly corroded so I had to replace it. There are two cables. I Know one is the battery cable. What is the smaller cable for?

That cable goes to the power distribution center....relays and such.

Thanks Buckroo!!