Explain column chromatography.

Hint: To explain column chromatography, we first explain the principle of chromatography and then explain it accordingly.
Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis.
It is a separation technique in which a mobile phase carrying a mixture is caused to move in contact with a selectively absorbent stationary phase.

Complete answer:
There are a number of different kinds of chromatography, which differ in the mobile and the stationary phase used.
Column chromatography is a technique in which the substances to be separated are introduced onto the top of a column packed with an adsorbent, passed through the column at different rates that depend on the affinity of each substance for the adsorbent and for the solvent or solvent mixture, and are usually collected in solution as they pass from the column at different times. Thus, the basic principle involved in column chromatography is to adsorb solutes of the solution with the help of a stationary phase and further separating the mixture into discrete components.
It is a solid - liquid technique in which the stationary phase is a solid and mobile phase is a liquid or gas.

Note: It is a solid - liquid technique in which the stationary phase is a solid and mobile phase is a liquid or gas. Hence, whenever any type of chromatography is asked to explain, always you must have to explain its principle.