Colloids are micron sized particles in dispersion, performing Brownian motion. They show scattering in the visible range, and slow diffusion (10-8 cm2/sec). The example of colloid ranges from examples in day to day life like blood, milk, paint etc to that in laboratory which charge stabilized colloids. It is our challenge to address the dynamics of such particles in presence of confining walls and external laser modulation. These systems falling in the class of soft matter systems are systems with typical interaction energy ~ kBT. Small perturbation affects systems substantially and one has to describe the phenomena at large length and time scales, which are classical systems and amenable to statistical mechanical treatment. Major challenges involve (a) Bridging the gap between molecular and relevant length scales of the system and (b) From molecular relaxation time to large time scales of the system.