Difference between presumptve and confirmatory tests?

Presumptive tests are initial screening tests used to suggest the presence of a substance, such as drugs or biological materials, based on observable reactions or indicators. They are generally quick, cost-effective, and can yield results without extensive analysis. Confirmatory tests, on the other hand, are more specific and definitive, providing conclusive evidence of the presence and identity of a substance through advanced techniques like chromatography or mass spectrometry. Confirmatory tests are typically conducted after a presumptive test has indicated a positive result.