| ## How the DCE Components Use Directory Services Service The Directory Service is a fundamental service that applications can rely on and use to their advantage. This topic describes how other DCE components use the Directory Service. The DCE Remote Procedure Call (RPC) interface facilitates the development and use of distributed applications that follow a client/server model. In the RPC model, clients are programs that make remote procedure calls, and servers are programs that carry out the procedures. The DCE RPC software stores information in the Directory Service about the addresses of RPC servers and the interfaces they support. When an RPC client wants to make a call to a particular server, it can query the Directory Service for the information necessary to contact that server. If the client wants to access a specific resource that is named in the Directory Service, it can query for that specific name. If a client application knows the type of service that it wants, such as C compilers, printers, or employee information, but does not know the address of a specific server, it can also use the Directory Service to find that information. The Security Service, which verifies the identity of users when they log in, uses the Directory Service to store the addresses of its authentication servers. The Distributed File Service (DFS) provides a location service for filesets (logical groups of files) so that users can access remote files as if they are on the local system. DFS uses the Directory Service to find out how to contact its fileset location servers. The Distributed Time Service (DTS) is responsible for synchronizing system clocks in the network. Synchronized clocks are important to any distributed application that needs to keep track of the order in which events occur across multiple systems. DTS uses the Directory Service to find out how to locate its time servers. ##