I'd start by focusing on the fact that spectroscopy is essentially a series of unrelated disciplines, since lots of phenomena can be described along a spectrum. So, for example, mass spec and NMR ...

Mass spectrometry (MS) is an analytical technique used to identify and quantify molecules based on their mass-to-charge ratio (m/z). It provides valuable information about the chemical composition, ...

Spectroscopy is an analytical technique that measures the interaction between electromagnetic radiation (or other energetic probes, such as electrons or ions) and matter as a function of wavelength, ...