Dielectric relaxation spectroscopy is an important tool to investigate collective polarization fluctuation dynamics of a wide variety of complex systems. Moreover, data from broadband DR measurements can explain the non-Markovian character of solvation response in complex systems that contain intermolecular H-bonding and ions. The intimate relationship between DR and solvation response then identifies the molecular motions that dictates the progress of a chemical reaction and unravels the associated nature of the underlying microscopic friction. DR experiments, however, monitor the long wavelength (𝑘𝜎 → 0, 𝑘 and 𝜎 being the wavenumber and particle diameter respectively) polarization fluctuations and therefore microscopic lengthscale information on dynamics involving a few to several molecules is missing. Often a wide frequency range, covering several orders of magnitude, is required to measure the full dynamics and the measured response is then assigned rather qualitatively to collective solvent rotation and translation coupled rotation. This is because DR experiments cannot separately measure the rotational and the translational solvent contributions and a measured relaxation time constant cannot be attributed cleanly to a particular type of molecular dynamics. This is where appropriate theoretical formalism and computations can contribute to separate the relative contributions from the total response.