What actually is scattering? What actually is scattering? What do we mean when we say "light is scattered by particles in air,..."?
I can understand reflection/refraction and am quite experienced with ray optics. 
I just want to know the basic understanding of what actually is happening with the wave. How is it any different from an irregular reflection in a broader sense?
 A: In classical mechanics, the basic scattering process is illustrated with two billiard balls hitting each other. It is called a scattering because there is a change of direction and a transfer of energy.
In light scattering  it is the change in direction of the energy that the light carries, an extension of the classical mechanics concept.

Light scattering is a form of scattering in which light in the form of propagating energy is scattered. Light scattering can be thought of as the deflection of a ray from a straight path, for example by irregularities in the propagation medium, particles, or in the interface between two media. Deviations from the law of reflection due to irregularities on a surface are also usually considered to be a form of scattering. When these irregularities are considered to be random and dense enough that their individual effects average out, this kind of scattered reflection is commonly referred to as diffuse reflection.

In quantum mechanics  the scattering of particles from each other  and off  fields  is described by quantum mechanical equations, where only the probability distribution of the scattered products can be calculated and checked against measurements. For example the quantum mechanical of photon off a nucleus. Feynman diagrams help in these calculations.
A: As I understand it the process of 'scattering' is any series of reflections and refractions such that the energy that was once condensed such that it would 'hit' a small area will now 'hit' a larger area.
