A Binder is an immediate but temporary insurance coverage provided for a limited time. A Binder covers the insured temporarily until a formal policy is issued.
Mostly, insurance companies issue binders before a formal policy is issued. You would need an insurance binder for almost every type of insurance ranging from house insurance, life insurance, health insurance, to auto insurance etc.
Example:
Alex has been provided with a 10 days insurance binder until his past insurance history could be researched. During this period, Alex will receive same rights and coverage as one receives with a regular insurance policy.