This document discusses optical rotatory dispersion (ORD) spectroscopy and circular dichroism (CD) spectroscopy. It defines ORD as the rate of change of specific rotation with wavelength, which can be measured using a polarimeter. Key concepts discussed include plane polarized light, optical activity, specific rotation, circular birefringence, and optical rotation. It also discusses the fundamentals of CD spectroscopy and the phenomenon of cotton effects seen in CD spectra.