Description:This book presents a novel approach to umbral calculus, which uses only elementary linear algebra (matrix calculus) based on the observation that there is an isomorphism between Sheffer polynomials and Riordan matrices, and that Sheffer polynomials can be expressed in terms of determinants. Additionally, applications to linear interpolation and operator approximation theory are presented in many settings related to various families of polynomials. Presents a novel approach to umbral calculus based on linear algebra Covers connections with interpolation and approximation theory Of interest to graduate students and researchers in analysis and numerical mathematics