Vibrational Absorption Spectroscopy is a technique in the field of spectroscopy used to study molecular interactions by analyzing their vibrational spectra. This method focuses on the vibration of atoms or groups of atoms within a molecule.

The fundamental principle is that each molecule has unique vibrational energy levels depending on its chemical bonds and molecular structure. When exposed to electromagnetic radiation, such as infrared light, the molecule absorbs energy that matches its vibrational frequency.

These energy changes can be measured and represented as an absorption spectrum, providing valuable information about chemical bonds, molecular structure, and the composition of the material.