Among the many applications of spectroscopy, we encounter different types of resolution ranging from temporal, spatial, and spectral resolution. When evaluating a spectrometer instrument, the optical resolving power of the instrument is key. This is known as spectral resolution and is normally defined as the minimum spectral separation between peaks that the instrument can resolve. Depending on the application, resolution can be an important parameter. For a lot of standard applications range and sensitivity are the main parameters, but as soon as peaks contain the application information (LIBS, Raman, plasma, laser, etc.) resolution becomes an important parameter. Basically, resolution states how well peaks can be seen, distinguished, and separated from each other.