Warranties: Strict promises made by the insured in the policy concerning the risk (e.g., a commercial building has working sprinklers). A breach of a warranty, even if immaterial to the loss, can void the policy.
Representations: Statements of fact made by the applicant during the application process (e.g., the applicant states they are a non-smoker). Misrepresentation only voids the policy if it is material and fraudulent.