What is the difference between scattering and backscattering? I sometimes hear people talking about scattering and backscattering, but I really cannot distinguish between the two?
Can some one please explain what is meant by these two concepts from a physical point of view?
 A: Backscattering is a type of scattering in which the momentum's direction of the scattered particle or photon changes in a way that the particle's direction gets reversed (head collision of a ball and wall) or the photon is reflected back towards its source (so you can see yourself in the mirror).
Backscattering is one of the ways that is used in far-detection; you send a laser and it interacts over a range of several meters with the material under study and during this interaction a backscattered light (which has specific characteristics for each material) moves back towards the laser source, where you have placed your detector as well, then you can collect it and study the material.
In general scattered particles' momentum defines this nomenclature; backscattering and forward-scattering (less used). 
A: There's no difference in the physics of scattering and backscattering. In both cases the interaction of your probe particle with a substrate scatters it through some angle $\theta$. If $\theta$ is around 180º we tend to call it backscattering, otherwise it's just scattering.
The terms tend to be used to describe the experimental technique rather than than the physics. For example Rutherford backscattering spectroscopy is a common technique for measuring the structure of material. As the name suggests it works by measuring the energies of particles scattered by 180º.
