What is anisotropy? Explain.

(N/A) When a substance possesses different magnitudes of physical properties such as electrical conductivity,refractive index,and thermal expansion along different directions,it is said to be anisotropic,and this property is known as anisotropy.
Anisotropy in crystals is due to the different arrangement of particles along different directions. The figure shows a simple two-dimensional pattern of the arrangement of two kinds of atoms. $A$ mechanical property such as resistance to shearing stress might be quite different in two directions $AB$ and $CD$. Deformation in the $CD$ direction displaces a row which has two different types of atoms,while in the $AB$ direction,rows made of one type of atoms are displaced.