Any irregularity in the pattern of crystal arrangement in a solid lattice is called imperfection in solids. The occurrence of defects takes place when crystallization (the process of formation of crystals) occurs at a very fast or at an intermediate rate.
Basically, defects fall out in two forms:
When the irregularities exist from the ideal arrangement around a point or an atom in solids, the defect is known as a point defect. Types of point defects are:
When the deviation from the ideal arrangement exists in the entire row of lattice points, the defect is called line defect.