Column chromatography is a technique used to separate mixtures of compounds based on their interactions with a stationary and mobile phase. The mixture is dissolved in a mobile phase and passed through a column packed with a stationary phase. Compounds are separated as they travel through the column at different rates depending on how strongly they interact with each phase. Stronger interactions with the stationary phase cause slower movement through the column. Column chromatography can be used to purify compounds and is influenced by the selection of the stationary and mobile phases based on properties of the compounds.