Answer:
The answer depends upon the type of insurance involved.
1. Property damage coverage (such as auto and homeowners) have deductibles. A deductible is the amount of money that the insured has to pay toward the cost of repair or replacement before the insurer's liability to pay is triggered. The deductible is specified in the insurance policy. It is also one of the factors that you, the insured, select when application for the policy is made. In general, the greater the deductible, the lower the premium.
2. Health insurance coverage usually also specifies a deductible. This works in essentially the same way as described above. However, heath insurance usually also specifies a "copayment". This is the percentage of every covered expense for which you, the insured are personally liable. Stated otherwise, if the policy has a 20% copayment, the insured pays 20% of the covered expense and the insurer pays the remaining 80%.