Client-server application model

A client-server application model is a combination of the following items:

• A software component with a user interface on a client computer
• A software component on a server that processes and stores information
• A communications mechanism between the client and the server.

The user works at the client computer, which is "serviced" by the server.

Simple client-server model


Typically, the client and server components are on different computer systems, and the communications mechanism is based on some form of networking technology, but it is possible to have both the client and server on the same host simply communicating between processes.

To make the development of client-server applications easier, an application programming interface (API) is used. Typically, the server is designed first, and its functionality is structured into a set of "commands." These commands are programmed into an API, which becomes the "language" for interacting with the server. When a client wants the server to do something, it makes a request through the API. The API handles all of the communications and operating system functions, gets the server to perform the task, and returns the appropriate information to the client. When the client software is developed, the programmer does not need to know any of the details of the server environment or communications mechanisms.

The  AR System server has a fully defined API that is common to all server platforms, both Windows and the UNIX platforms. The  AR System client tools all use this API for interaction with the servers. They all speak the same language and are completely interchangeable. A client on any platform can work with a server on any platform. As long as a client can connect to an  AR System server , it can communicate all its requests and receive the replies using this common language. The client does not need to know on which platform the server is running. It also does not need to know about other clients that are using the same server.

The  AR System API is defined by a strict set of programming functions and data structures, which are documented in AR System C API functions and Data structures. The API is implemented as a C library and associated files that can be linked into your programs. Third-party programs linked to the  AR System API library become clients to an  AR System server .

AR System  API