Directory-Based Protocols are communication methods used in distributed systems to manage and locate resources efficiently. These protocols maintain a centralized or decentralized directory that keeps track of the locations of various resources, such as files or services, allowing users to quickly find and access them. In a directory-based system, when a user requests a resource, the protocol checks the directory to find its location. This approach reduces the time and effort needed to search for resources, improving overall system performance. Examples of such protocols include Domain Name System (DNS) and Lightweight Directory Access Protocol (LDAP).