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Chemical shift (δ) is reported in ppm relative to TMS at 0 ppm, so values can be compared across spectrometers with different field strengths. A higher δ is downfield and indicates deshielding; a lower δ is upfield and indicates shielding. Typical ¹H regions include aromatic signals at 6–8 ppm, aldehydes at 9–10 ppm, and carboxylic-acid OH signals at 10–13 ppm, while ¹³C benchmarks span distinct regions for alkyl, sp, aromatic/alkenyl, and carbonyl carbons. Chemical shifts are influenced by nearby electronegative atoms, hybridization, ring-current anisotropy, and hydrogen bonding. The lesson also connects peak behavior with symmetry, exchangeable protons, solvent signals, temperature, DEPT spectra, and the distinction between chemical shift and splitting.