Discretization refers to repserenting a conversion of continuous quantity quantities using into an expression using discontinuous (discrete) values.

Because values handled as only discrete values can be used in computational calculations, must be discrete values, continuous values in governing equations with continuous values cannot be calculated. To execute calculations, discrete values obtained by discretization of governing equations are used to construct algebraic equations, which can be applied to calculations. To execute calculations, discrete values must be obtained by discretizing governing equations, which can be used to construct and converting them into algebraic equations.