The book "Differential Equations and Numerical Analysis" offers a comprehensive introduction to the theory of differential equations and numerical analysis. It is aimed at both students and researchers who wish to engage with singular perturbations and their applications in various problem areas. Written by recognized experts in their field, the work provides valuable insights into the construction of numerical methods for solving differential equations. The authors present new contributions to the topics of differential equations and singular perturbation problems, enabling readers to develop a deeper understanding of the underlying concepts. The chapters are supplemented with illustrative tables and graphics that clarify the theoretical content and support the application of the methods.