Functionally-Enhanced Derivative Spectroscopy (FEDS) is a simple, fast and easy to use deconvolution method based on the combination of derivative spectroscopy and simple functional algorithms. As analytical technique has demonstrated to be a powerful tool for analysis of spectral signals of mid-infrared spectra. In specific, FEDS produces the separation of overlapped signals through a transformation of the spectrum that consists of making the signals more acute and intense depending on the signal to noise ratio. The purpose of this review is to provide a theoretical and applied overview of ability of FEDS for the improving spectral analysis of complex samples with importance in materials, food and biomedical engineering, environmental sciences, microbiology, biotechnology and biological, chemical and physical science, among others