Until now, no book addressed convexity, monotonicity, and variational inequalities together. This book covers all three topics, including new variational inequality problems defined by a bifunction. It deepens your understanding of various classes of problems, such as systems of nonlinear equations, optimization problems, complementarity problems, and fixed-point problems. The first part of the book focuses on generalized convexity and generalized monotonicity. The second part offers insight into variational inequalities and optimization problems in smooth as well as nonsmooth settings.