A misrepresentation is a statement, whether written or oral, that is false. Generally speaking, in order for an insurance company to void a contract because of misrepresented information, the information in question must be material to the decision to extend coverage.
Concealment, on the other hand, is the failure to disclose information that one clearly knows about. To void a contract on the grounds of concealment, the insurer typically must prove that the applicant willfully and intentionally concealed information that was of a material nature.