The variety of combinatorial properties of nonnegative matrices is widely discussed in the mathematical literature, and there are many papers on this topic. However, there are few monographs devoted to these properties of nonnegative matrices. This book fills that gap and presents a summary of the existing material. It provides an entry point into the subject and includes exercises to aid students. The authors focus on the relation of matrices with nonnegative elements to various mathematical structures studied in combinatorics. In addition to applications in graph theory, Markov chains,...