Proton Magnetic Resonance (PMR) is a technique used to study the structure and properties of molecules by using the magnetic properties of atomic nuclei. Synonyms for PMR include Nuclear Magnetic Resonance (NMR) spectroscopy, which is a more general term encompassing the study of other atomic nuclei as well. Other synonyms include Magnetic Resonance Imaging (MRI), which is a non-invasive medical imaging technique used to visualize the internal structure and function of the body using PMR. Another synonym is Magnetic Resonance Spectroscopy (MRS), which is a variant of NMR that is used to study the chemical composition of tissues and fluids in the body. Overall, these synonyms denote different applications of the same underlying technology used to explore the properties of atomic nuclei.