证件 (zhèngjiàn) is a general term for any official document that proves your identity or status, like a passport, driver's license, or student ID. It's broader than 身份证 (shēnfènzhèng, specifically a national ID card) and 证书 (zhèngshū, a certificate of qualification or achievement). Use 证件 when you mean 'ID documents' in general, not a specific type.