Chromatography is a method of separating and analyzing mixtures of chemical substances in a solution. It is based on the principle of differential solubility and/or adsorption of the individual components of a mixture to a stationary phase and a mobile phase. In chromatography, the sample mixture is first dissolved in a liquid or gas known as the mobile phase, which is then passed through a stationary phase, which is typically a solid or liquid material. The stationary phase is designed to selectively interact with some of the components of the sample mixture, causing them to separate from the rest of the mixture as the mobile phase flows through it. The different components of the mixture are separated based on their interactions with the stationary phase and the mobile phase, which can be adjusted by varying the chemical properties of the stationary and mobile phases. The separated components can then be analyzed or collected for further use. There are several types of chromatography techniques, including gas chromatography (GC), liquid chromatography (LC), high-performance liquid chromatography (HPLC), and thin-layer chromatography (TLC), among others. Each technique has its own advantages and limitations, and the choice of technique depends on the specific requirements of the analysis. Chromatography is widely used in analytical chemistry, biochemistry, pharmaceuticals, food science, and many other fields for the separation and analysis of complex mixtures of chemical substances.