Final answer:
The word 'insure' is used to protect against damage or loss, while 'ensure' is used to make certain of something.
Step-by-step explanation:
The word 'insure' is used when referring to protecting against damage or loss. For example, homeowners must insure their property to cover the cost of full replacement in case of any damage or loss.
On the other hand, the word 'ensure' is used to mean making certain or guaranteeing something. For instance, a policy can ensure that a bank doesn't incur a loss by providing financial protection in case of irreparable damage to a home.