Both are hierarchical controlled vocabularies for health sciences and have a similar facet structure. In fact, Embase was modeled on MeSH in 1988. Both also link to CAS registry and Enzyme Commission numbers. Over time, however, Embase has differentiated itself from MeSH. While it still includes all MeSH terms, it has become a more extensive thesaurus that facilitates a more intuitive way of exploring the literature. Learn more about the differences between Emtree and MeSH.