Tandem mass spectrometry is an analytical technique that employs multiple stages of mass analysis to characterize ions. It fundamentally involves isolating a specific precursor ion, inducing its fragmentation, and then analyzing the mass-to-charge ratios of the resulting product ions. This methodological approach is crucial for the identification, structural elucidation, and quantification of molecules, particularly in complex mixtures. Its key characteristic lies in the sequential mass filtering and fragmentation process, which yields detailed structural information and enables high sensitivity and specificity across various research fields, including proteomics, metabolomics, and small molecule analysis.