A catalytic converter is a device installed in the exhaust system of vehicles to reduce the emission of harmful gases into the atmosphere. It contains catalysts, such as platinum, palladium, and rhodium, which facilitate chemical reactions that convert toxic compounds in the exhaust, like carbon monoxide, nitrogen oxides, and hydrocarbons, into less harmful substances like carbon dioxide, nitrogen, and water vapor. This helps vehicles meet emission standards and reduces air pollution from automobiles.