A chromatogram is the visual output of a chromatograph, which is essentially the output of a chromatography run. Chromatography is a laboratory technique used to separate a mixture into its components. The mixture is dissolved in a fluid solvent called the mobile phase, which carries it through a system on which a material called the stationary phase is fixed. The stationary phase can be a solid, a liquid, or a gas, and it interacts differently with the components of the mixture, causing them to separate. The chromatogram is a two-dimensional plot with the ordinate axis giving concentration in terms of the detector response, and the abscissa represents the time. Different peaks or patterns on the chromatogram correspond to different components of the separated mixture. The chromatogram can be used as an analytical tool, feeding its output into a detector that reads the contents of the mixture. It can also be used as a purification tool, separating the components of a mixture for use in other experiments or procedures.