Mesh quality measures how suitable the cells of a mesh are for a numerical or geometric application. There is no single universal quality measure. Common measures penalize small angles, large ratios of longest to shortest characteristic lengths, or departure from a regular reference cell.
Quality requirements are commonly imposed during mesh generation because poorly shaped cells can degrade the accuracy or conditioning of the finite element method. A quality measure is normally chosen to match the cell type and the numerical method in which the mesh will be used.
