How do defects arise in crystals? State the types of defects.

(N/A) Crystalline solids possess short-range as well as long-range order in the arrangement of their constituent particles,yet they are not perfectly crystalline.
Generally,a solid consists of an aggregate of a large number of small crystals. These small crystals have defects in them. This happens when the process of crystallization occurs at a fast or moderate rate.
Defects are basically irregularities in the arrangement of constituent particles. There are two main types of defects:
$(i)$ Point defects
$(ii)$ Line defects
$(i)$ Point defects: These are the irregularities or deviations from the ideal arrangement around a point or an atom in a crystalline substance.
$(ii)$ Line defects: These are the irregularities or deviations from the ideal arrangement in the entire row of lattice points.