This book is a collection of works related to information contributed by multiple authors dedicated to the memory of Mark Burgin who passed away on February 18, 2023. Mark Burgin had a very wide range of research and philosophical interests which has a reflection in the very broad subject range of the contributions to this book honoring his memory as an outstanding member of the academic community. The book Understanding Information and Its Role as a Tool: In Memory of Mark Burgin has two parts which have self-explanatory titles classifying submissions into two categories. One of them is "Understanding Information: Theory and Foundations" and the other "Information Realm: Information as a Tool for Exploring Reality". The former is intended as an inquiry of the concept of information itself, the latter as an inquiry of the use of the concept of information as a methodological tool for diverse forms of inquiries. The book was originally planned together with Mark Burgin and only after his passing was transformed by its present editors into his memorial. It was intended as a means to promote and disseminate the results of the ongoing research on information stimulated, initiated, or influenced by the 2021 IS4SI Summit. In the present form it goes way beyond its original design to focus on the most recent developments in the fields of information study.