Thought-provoking discussions on conservation from various points of view. What is Conservation? is an unconventional introduction to the topic of conservation in all its forms, facilitated through discussions with MacArthur Fellows. The discussions took place in New York in the Spring of 2022 alongside an exhibition at Bard Graduate Center called "Conserving Active Matter.” This volume seeks to acquaint readers who are new to the subject by presenting it in its broadest sense, while also focusing on its greatest significance as described by MacArthur Fellows. It touches on aspects of conservation through the lenses of art, science, literature, poetry, humanism, and more. It also features photographs from the accompanying exhibition.