Microbial interactions is a research field within microbiology and ecology dedicated to studying the diverse relationships, associations, and exchanges occurring between microorganisms, including bacteria, archaea, fungi, protists, and viruses. This concept investigates the mechanisms and outcomes of these interactions—ranging from mutualism and commensalism to competition, antagonism, and parasitism—and their fundamental roles in driving ecosystem processes, shaping microbial community structure, influencing host health, and impacting global biogeochemical cycles.