A dispersion is a system in which particles are dispersed in a continuous phase of a different composition (or state). A dispersion is classified in a number of different ways, including how large the particles are in relation to the particles of the continuous phase, whether or not precipitation occurs, and the presence of Brownian motion.

Dispersions do not display any structure i.e the particles dispersed in the liquid or solid matrix are assumed to be statistically distributed.The percolation theory usually describe the properties if dispersions. Dispersions are plentiful in types and in use all over the world in innumerable applications.

Dispersion is a process by which agglomerated particles are separated from each other and a new interface, between an inner surface of the liquid dispersion medium and the surface of the particles to be dispersed.

Dispersions have structures very much different from any kind of statistical distribution, but in contrast very much showing structures similar to self-organisation, which can be described by non-equilibrium thermodynamics.

Dispersive applications of nanoparticles include optical, thermal, and diffusion barriers. Other applications include imaging ink jet materials, electrophotography, pharmaceuticals, flavor enhancers, pesticides, lubricants, and other proprietary applications specific to industry.