The Mohr-Coulomb Failure Criterion is a fundamental concept in soil and rock mechanics that describes how materials fail under shear stress. It combines the effects of normal stress and shear stress to predict the failure of materials, particularly in geotechnical engineering. The criterion is represented graphically by a failure envelope, which is a straight line in a plot of shear stress versus normal stress. This criterion is defined by two key parameters: cohesion and internal friction angle. Cohesion represents the inherent strength of the material when no external forces are applied, while the internal friction angle indicates the material's resistance to sliding along internal surfaces. Together, these parameters help engineers assess the stability of slopes, foundations, and other structures.