Genus Balanus refers to a group of small, sessile crustaceans commonly known as barnacles, which are found attached to rocks, ships, and other hard surfaces in marine habitats around the world. Synonyms for this taxonomic genus include Cirrhipedium, Conchoderma, Coronula, and Tetraclita. These synonyms come from various taxonomic revisions and reclassifications of the group over the years, based on morphological, molecular, and ecological data. While barnacles may appear to be simple organisms, they play important roles in marine ecosystems as filter feeders, food sources for other sea creatures, and substrates for epibionts. Understanding the diversity and relationships of species within the genus Balanus and related groups is essential for effective conservation and management of coastal and oceanic environments.