Paper chromatography is a technique used to separate mixtures based on differences in how components partition between a stationary phase (filter paper) and mobile phase (solvent). It involves applying a sample to a strip of paper and developing it by allowing the solvent to travel up the paper. This causes the different components to separate into bands at different distances based on how strongly they are retained by the paper. Paper chromatography is widely used for qualitative analysis and identification of organic and inorganic compounds in mixtures.