"Bulletproof" is a term commonly used to describe materials or products that are resistant to bullets or projectiles. This concept is often applied to body armor, vehicles, and protective gear designed to safeguard individuals from gunfire. Bulletproof materials typically include layers of strong fibers, such as Kevlar, or hard materials like ceramic. In a broader context, "Bulletproof" can also refer to strategies or plans that are highly reliable and resistant to failure. For example, a business plan that is considered bulletproof would have thorough research and contingency measures in place to address potential challenges.