Define Chromatography - Basic Separation Technique?

Chromatography is the most effective technique for the separation, purification and identification of one or more biological compounds from a mixture of compounds. It is used for the separation of large to smaller amounts of materials, such as proteins, amino acids etc. The choice of a particular type of chromatography depends largely on the chemical nature or complexity of the material and sometime need two or three types of chromatography sequentially to achieve the complete purification of a compound.