In this talk, I will begin with a brief introduction to the fundamental strategies used by both theoretical and experimental communities to identify hadronic states in the context of hadron physics. I will then focus on two recent studies concerning the spectroscopy of charm and charm-strange mesons. The first involves the long-standing puzzle surrounding the nature of the D_S1(2460), one of the earliest observed heavy-flavor mesons exhibiting properties beyond the expectations of the quark model. We demonstrate that its isospin-conserving three-body decay provides a valuable benchmark for probing its internal structure. The second study concerns the identification of the two-pole structure of the D₀^*(2300), incorporating the latest lattice QCD data. Both examples highlight the growing significance of hadronic molecular configurations-bound states driven by one-hadron exchange interactions – as an essential component of hadron spectroscopy, particularly in the heavy quark sector.