An Owner's Title Insurance policy insures that a buyer will receive title to the real estate free and clear of any matters except those listed. The policy insures that the title to your property is yours and that you own it subject to those matters stated in the policy. It insures that the insured will be protected from 
loss or damage as a result of title defects.
Your owners policy is purchased at the time of settlement for a one-time fee. The insurance stays in effect for the entirety of your life and even passes on to your heirs.