Chromatography is a widely used technique that separates and identifies the components of complex mixtures. It works on the principle of differential movement of compounds through a stationary phase when influenced by a mobile phase. Depending on the interaction between the mixture’s components and the phases, the compounds move at different rates, leading to their separation. There are several types of chromatography, including liquid chromatography (LC), gas chromatography (GC), thin-layer chromatography (TLC), ion-exchange chromatography, and size-exclusion chromatography. Liquid chromatography (LC) is commonly used to analyze liquid mixtures in fields like pharmaceuticals and environmental studies. Gas chromatography (GC) is ideal for analyzing volatile compounds, such as in environmental monitoring or forensic analysis. Thin-layer chromatography (TLC) is a simpler and more affordable method for qualitative analysis, like identifying compounds or tracking reaction progress. Ion-exchange chromatography separates charged particles, and size-exclusion chromatography is used for separating molecules based on size, often applied in protein and polymer analysis. Chromatography instruments typically include columns, detectors (such as UV/Vis or mass spectrometers), pumps, and injectors. The choice of method and equipment depends on the specific analysis needs. This technique plays a crucial role in areas like drug development, food safety, and biotechnology, where precise separation and identification of substances are critical.