Why it is called chromatography separation?

Answer 1

Because we are using this technique to separate mixtures of substances into their components

Answer 2

Chromatography is called a separation technique because it separates different components of a mixture based on their different affinities for the stationary phase (solid or liquid) and the mobile phase (gas or liquid). As the mixture passes through the stationary phase, the components interact differently and move at different rates, leading to separation.