An application server is a type of server that stores, hosts and manages all necessary software tools and back-up support required to run an application. This repository enables the server to install and operate the application when requested by a user. When an application is downloaded and installed by a user, the server provides all necessary backup documents to ensure the application’s smooth installation. An application server could be connected to the terminal or end user’s computer through enterprise systems, intranet or the Internet.
An application server can furnish HTTP content such as web servers, but it can also support other protocols such as Remote Method Invocation (RMI)/Remote Procedure Call (RPC). These protocols are used to communicate with remote objects. In other words, these connect various parts of an application residing on different computers or sites connected to each other. The application interface is the middleware connecting the various computers. RMI/RPC are just a couple of the several application-level services an application server supports.