The deductible or retention on your policy both refers to the amount of money that must be paid by you (the insured), out of pocket, per claim before the policy limits will kick in and the carrier will begin paying.
Deductibles:
are usually found on Occurrence policies
are funded by the carrier and collected later from the insured
reduce (or erode) the limit available to pay claims
Retentions:
Also known as SIR or “Self-insured Retention”
are usually found on Claims Made policies
are paid directly by the insured
do not reduce the available limit