What are three types of prokaryotes?

Three types of prokaryotes include bacteria, which are ubiquitous and play vital roles in ecosystems; archaea, which often thrive in extreme environments and have unique biochemical properties; and cyanobacteria, which are photosynthetic bacteria that can produce oxygen and are important for nitrogen fixation in aquatic ecosystems. Each of these groups exhibits distinct characteristics and adaptations that enable them to thrive in various habitats.