High-performance liquid chromatography (HPLC) columns are critical components in the HPLC system, used to separate, identify, and quantify compounds in a mixture. These columns are typically filled with a stationary phase, which can be silica-based or polymer-based particles. The choice of stationary phase and particle size determines the column's selectivity, resolution, and efficiency. HPLC columns are available in various dimensions, with the most common types being analytical, preparative, and guard columns. The separation process occurs as the sample mixture is carried through the column by a liquid mobile phase under high pressure. HPLC columns are essential in pharmaceuticals, environmental testing, food analysis, and chemical research for their ability to provide precise and reliable separation and analysis of complex mixtures.