This monograph is devoted to the study of multiscale model reduction methods from the point of view of multiscale finite element methods.Multiscale numerical methods have become popular tools for modeling processes with multiple scales. These methods allow reducing the degrees of freedom based on local offline computations. Moreover, these methods allow deriving rigorous macroscopic equations for multiscale problems without scale separation and high contrast. Multiscale methods are also used to design efficient solvers.This book offers a combination of analytical and numerical methods...