Application server is a application with three tier concept like client-server concept. The application server concept in the actually is a simple. Its just client-server methodology. Which surrounding operation ofapplication server it is entangling transfer of information between computers for request about certain information. Then in the server side, server giving some information according to the request some user when at the same time. The conclusion about this is application server is a server have a function for to serves any request of client to web pages. If we developed some application server for running , we requires about where the application or where the project will be deploy. For answers this question we must have application server such us apache tomcat, IIS, Xitami and much more. The apache tomcat engine is an open-source package developed as part of the Apache Software Foundation's Jakarta project. It is the official reference implementation for both the servlet and JSP specifications. However, it's not just a research project; it's capable of being deployed in production environments and offers many of the same features as commercial Web application containers. To use apache tomcat, you need a full Java Development Kit (JDK) installed on your system. The smaller Java Runtime Environment (JRE) does not include a Java compiler, which is necessary for compiling JavaServer Pages. If you get an error telling you there is no compiler, you probably have the JRE edition. Java application server is some application will running in a server but any client get more information from the server and the programming language use with java. In the java we can user much framework for some java application server such us spring, hibernate, and much more. I will introduce about spring with my knowledge. Spring is one of application framework for java application server with base on java language programming, precisely J2EE. What Is a application framework? My concludes application framework is a group of order or standard accompanied with library, applied to usefull, quickens or makes application development so that amendable again easily later.