Before revision: Next-generation catalogs The newest generation of library catalog systems are distinguished from earlier OPACs by their use of more sophisticated search technologies, including relevancy ranking and faceted search, as well as features aimed at greater user interaction and participation with the system, including tagging and reviews.
After revision: , typically called discovery system (or discovery layer),Next-generation catalogs The newest generation of library catalog systems are distinguished from earlier OPACs by their use of more sophisticated search technologies, including relevancy ranking and faceted search, as well as features aimed at greater user interaction and participation with the system, including tagging and reviews.