The client/server model for application processing
The client server model in application processing is complex as it involves many different components interacting with each other. First, the client computer, requests information through the TCP/IP layer of a network which delivers the message to the web server. The web server then distributes this message to the API or CGI, which then routes the message through the appropriate middleware application layer to the RDBMS and database.
The return packet is then redistributed back to the client computer and is returned back through the paths the request took to reach the server. Once the message is passed though the middleware, API/CGI, server, network, and then to the user, the client can then view the response to the original message, which can either be connectivity, text, data, status, or other types of information depending on the application requesting information on the client computer.