Chromatography is a technique used to separate and analyze mixtures of chemical compounds. It involves passing a mixture through a column packed with a stationary phase, which selectively retains certain components based on their interaction with the stationary phase. The separated components are then eluted from the column one at a time, allowing for analysis and identification of each component. There are several types of chromatography, including gas chromatography (GC), high-performance liquid chromatography (HPLC), and thin layer chromatography (TLC).