Chromatography works by separating the soluble substances in a solvent from each other using another material like chromatography paper. Chromatography works like a hurdles race. The solvent and substances in the mixture travels up the material.
The different substances will take different amounts of time to pass through the material. The substance that gets obstructed least by the material will move furthest while the substance that gets obstructed more will travel the least distance. We can tell substances apart by calculating their Rf values.
Rf = distance moved by the compound ÷ distance moved by the solvent