Traditional imaging systems generally provide 1-channel (grayscale) or 3-channel (RGB) images of scene with a large number of spatial channels. Alternatively, spectroscopy systems offer many spectral channels that provide detailed information about the material properties of a subject, but yield little spatial information. Recently, several imaging techniques have been developed that seek to combine the spatial resolution of traditional imaging systems with the spectral discrimination of a spectroscopy system. Advances in detector technologies and increased availability of truly hyperspectral imaging sensors have opened new imaging capabilities and solutions in many fields including medicine, agriculture, and defense.  In this talk, I will discuss the fundamental concepts of one such technique, Coded Aperture Spectroscopy (CAS). I will provide background in the imaging physics of the technique, and describe its application to diffuse source spectroscopy, multiplex spectroscopy, and methods of 2D hyperspectral imaging.