"All vows, prohibitions, oaths, consecrations, vows of korbon, or equivalent terms that we may vow. swear, consecrate, or prohibit upon ourselves, from the last Yom Kippur until this Yom Kippur, may it come upon us for good - regarding them all, we regret them henceforth. They will be permitted, abandoned, cancelled, null and void, without power and without standing. Our vows were not valid vows; our prohibitions were not valid prohibitions; and our oaths were not valid oaths."
"Kol Nidrei is to be understood as seeking G-d's mercy for vows taken upon oneself which relate only to personal vows and oaths. Commitments and vows taken as obligations to others out to be kept even if the cost of such commitment is high."
~Kol Nidrei Service Siddur