Any application you run on Windows NT can take advantage of networking resources because networking components are built into Windows NT. In addition, Windows NT includes several mechanisms that support and benefit distributed applications.
A distributed application is one that has two parts—a front-end to run on the client computer and a back-end to run on the server. In distributed computing, the goal is to divide the computing task into two sections. The front-end requires minimal resources and runs on the client's workstation. The back-end requires large amounts of data, number crunching, or specialized hardware and runs on the server. A connection between the client and the server at a process-to-process level allows data to flow in both directions between the client and server.
Microsoft Mail, Microsoft Schedule+, SQL Server, and SNA Server are examples of distributed applications.
As described in the next section, Windows NT includes NetBIOS and Windows Sockets interfaces for building distributed applications. In addition, Windows NT supports peer-to-peer named pipes, mailslots, and remote procedure calls (RPC). On Windows NT, for example, an electronic mail product could include a messaging service using named pipes and asynchronous communication that runs with any transport protocol or network card.
Of named pipes, mailslots, and RPC, RPC is the most portable mechanism. RPCs use other interprocess communication (IPC) mechanisms — including named pipes and the NetBIOS and Windows Sockets interfaces — to transfer functions and data between client and server computers.
Named pipes and mailslots are implemented to provide backward compatibility with existing LAN Manager installations and applications.
For more information about using distributed applications with Windows NT, see Chapter 8, "Client-Server Connectivity on Windows NT."