A server is a program or computer which connects applications across different devices and distributes hardware resources to achieve maximum efficiency and convenience. Furthermore, an application server acts as the middleman in inter-computer communication. Alternatively said:
An application server is a server program in a computer in a distributed network that provides the business logic for an application program, http://searchsqlserver.techtarget.com/definition/application-server
An application server is a server which provides software applications with services such as security, data services, transaction support, load balancing, and management of large distributed systems. http://en.wikipedia.org/wiki/Application_server
The Internet functions on a three-tier (three-level) structure, the tiers being 1) the user interface or client, 2) the business logic application server, and 3) the larger database and transaction server. The interface, most commonly a web browser or some other application for viewing web pages, translates computer outputs into recognizable human content and inputs into computer commands. These commands are then processed and transmitted by the application server, which provides the necessary structure and security to ensure the information reaches its intended recipient as well as applying any kinds of data and logical transformations needed for the application to make decisions. The third-tier server in turn performs data operations based on input from the application server, stores data and sends the results back out though the application server and the loop is complete. Different approaches to forwarding requests and web pages include the Common Gateway Interface (CGI), Active Server Pages (ASP) by Microsoft, and Java Server Pages (JSP).
Another, more obvious meaning behind an application server is a server that runs a specific program, http://www.wisegeek.com/what-is-an-application-server.htm. Such example would include word processing or desktop publishing applications which operate from a single server. Thus, all users from the specific company or institution would have continuous access to the programs simply by logging on. Older versions of this server type accommodate a complete operating system and terminals connect to it for their most basic functions. This architecture allows resources to be distributed to those who need them the most and for the IT department to monitor computer demands.
Why should companies use application servers?
Data and Update Sharing: Most corporations frequently distribute certain files, like the coming-year budget, and ideas in need of feedback, and update the company applications. In order to ensure everybody has the correct version, application servers are a one-stop place where all such changes can be made.
Easy Layout Change: When renovations have to be made, or the hardware improved, it is much easier to update and configure only a single device
Improved Security: It is much harder to achieve end-point (terminal) security because users pay less attention than IT specialists and their hardware has less “fire power” than it is to protect a centralized server.
Performance: Corporate environments frequently utilize extremely demanding applications and through an application server, which has superior computing capabilities, employees will perform their tasks much quicker compared to a normal PC terminal.
Cost Savings: All such improvements in the digital infrastructure predispose to huge savings. By distributing the software from one place companies will spend less on licenses and replacement of underperforming parts, losses on hacker attack will be minimized and the corporation will gain a competitive advantage due to improved efficiency.
Examples of application servers
IBM WebSphere Application Server. Built using open standards like Java EE and XML, IBM’s WAS runs on Windows, AIX, Linux, Solaris and i/OS. The software boasts efficiency, flexibility and intelligent management to ensure that business costs are kept at a minimum. It reduces server downtime and overloads by consolidating workloads. Innovative solutions improve user experience, while the open standards-based programming facilitates diverse developer skills. Higher application security and the granular control complement the backwards compatibility features, and the WAS lets legacy and packaged applications be re-used, thus lowering costs even further.
The JAVA Platform, Enterprise Edition. Commonly known as Java EE, it was developed by Oracle and “provides an API and runtime environment for developing and running enterprise software”, http://en.wikipedia.org/wiki/Java_Platform,_Enterprise_Edition. It offers an API for fault-tolerance, multi-level structures, object-relation mapping and web services. Being the industry standard for enterprise Java programming, the Java EE 6 Web Profile can create capable web application, thanks to its improved interface and fewer XML configurations. Because of the ubiquity of the Java EE, it has come to be synonymous with the term application server. The newest update, as of February 29, 2012, includes the GlassFish Server 3.1.2 with better clustering, secure installation, faster administration console startup and command line feature parity.
The Application Server role of Windows Server 8. “The new version of Application Server provides an integrated environment for deploying and running custom, server-based business applications”, http://technet.microsoft.com/en-us/library/cc754024(v=ws.10).aspx . The server uses the Internet Information Services, the Microsoft .Net Framework, ASP.NET, COM+, Message Queuing and services built with the Windows Communication Foundation. This function should be utilized when applications, developed either within or for the organization, require specific role service. Windows Application server can deploy demanding business program and service simultaneous requests. Similarly, programmers would enjoy the simplified method to connect to other server applications, while the Add Roles Wizard effortlessly installs the necessary features, making it easy to setup any computer as such a server.
In conclusion, application servers have been around for a long time and have certainly contributed to the users’ internet experience. Be it to maintain security, provide faultless data retrieval or simply fast browsing, application servers truly deserve to be called the middleman of browsing. Yet, their other function of providing a single application to a number of users should also not be underestimated.