The primary types of chromatography include gas chromatography (GC), liquid chromatography (LC), and high-performance liquid chromatography (HPLC). Gas chromatography separates volatile compounds by their affinity for a stationary phase within a gas stream. Liquid chromatography employs a liquid mobile phase to separate components based on their interaction with a stationary phase. HPLC, a subset of liquid chromatography, utilizes high-pressure pumps and small particle size in the stationary phase for enhanced efficiency. Other notable variations include thin-layer chromatography (TLC) and affinity chromatography, each serving specific purposes in separating and analyzing diverse compounds across pharmaceutical, environmental, and biochemical applications.