[Terminology] Colloid and colloidal system
Colloid definition: the particles have at least one dimension within 1000nm to 1nm range or 100nm to 1nm range. Colloid is a presence status of substance.
Colloidal system definition: the system containing colloids.
Colloidal system is fine dispersed multiphase system. Typically, colloidal system is non-uniform.
Colloidal systems are diverse existences.
When Dispersed phase and dispersion medium are gaseous states, can not form the colloidal system; in the remaining eight combinations states, can form the colloidal system.
Particles of polymer solution accord with definition of colloid; many properties of polymer solution are similar to colloid; the difference is that polymer solution is a true solution.
Broadly, polymer solution is the colloidal system.