“The publication is mainly intended for readers who want to get briefly acquainted with the classical theory of SPDE before studying modern approaches to SPDEs like the rough paths theory, the theory of regularity structures or the method of paracontrolled distributions.” (Martin Ondreját, zbMATH 1511.91001, 2023)“This monograph is a nice addition to the existing literature on SPDEs, complementing it by presenting a variety of variational methods available for nonlinear SPDEs.” (Kristin Kirchner, SIAM Review, Vol. 65 (1), March, 2023)“This book … serves as a solid introduction to recent developments in the classical theory of stochastic partial differential equations. This book is a nice introduction to the subject matter for those unfamiliar with the topic. The author is direct, and the small size of the book makes it very approachable. Plenty of references are providedfor those who wish to dive deeper into the topic.” (Bill Satzer, MAA Reviews, June 6, 2022)