A application server is a web server that manage the server-side scripts by an unit called a web applications.
An application server is a platform which support, manage and run many applications.
For the developers, it provides a set of common components that you will find in any applications development. They implement services like:
The software developers:
And Thin-client multi-tiered applications word then easier to write because they don't need to think about
The term application server took on the meaning of web applications, but has since evolved into more of a comprehensive service layer.