Electromagnetically induced transparency (EIT) and Autler–Townes splitting (ATS) are two similar yet distinct phenomena that modify the transmission of a weak probefield through an absorption medium in the presence of a couplingfield, featured in a variety of three-level atomic systems. In many applications it is important to distinguish EIT from ATS splitting. We present EIT and ATS spectra in a three-level cascade system, involving cold cesium atoms in the S 35 1 2 Rydberg state. The EIT linewidth, γEIT, defined as the full width at half maximum of the transparency window, and the ATS splitting, γATS, defined as the peak-to-peak distance between AT absorption peaks, are used to delineate the EIT and ATS regimes and to characterize the transition between the regimes. In the coldatom medium, in the weak-coupler (EIT) regimeγEIT≈ A+B (c 2 W+ p eg 2 W G), whereΩc andΩp are the coupler and probe Rabi frequencies, Γeg is the spontaneous decay rate of the intermediate 6P3/2 level, and parametersAandBthat depend on the laser linewidth. We explore the transition into the strong-coupler (ATS) regime, which is characterized by the relationγATS≈ Ωc. The experiments are in agreement with numerical solutions of the Master equation. Our analysis accounts for non-ideal conditions that exist in typical realizations of Rydberg-EIT, including laser-frequency jitter, Doppler mismatch of the utilized two-color Rydberg EIT system, and strong probefields. The obtained criteria to distinguish cold-atom EIT from ATS are readily accessible and applicable in practical implementations.