Trying to figure out Java EE

[guyafe]

Hi all,
I am trying to understand what is Java EE and what is the difference between it and Java SE.
Googling out let me understand that EE is the SE, adding wider API: Mostly for server applications. Am I right?

Also, I couldn't understand the meaning of Application Server? I sae some servers such as JBOSS and GlassFish but couldn't understand what they are ment for?
Are they useful? Who is using them?
Are these just generic servers used for some POCs?

I am feeling that I am missing here something much deeper.

Thanks for any clarification,
Guy

[javinpaul]

You are right:

1) J2EE is container based and Application server provides vital services like DB connection pooling, transaction management etc.

2) J2EE application are mainly web application or ejb application .war or .ear or web services they require application server to run. web application can also run on web server like tomcat.

3) On broader term J2EE is collection of technology e.g. Servlet, JSP and EJB for building http based application.

[guyafe]

Thanks,
Can you please tell me some more about application servers?
I understand the goal of, say, web server (Tomcat, IIS, etc.) but not of application server.
Who is using it? What does it do?
Can you give me a usage example?

Thanks,
Guy

[nambill]

application server = web server + container for dynamic server side scripting (JSP, Servlet for Java; C#, ASP.NET for .NET)
a web server just serves HTTP and pure HTML. In order to execute JSP, Servlet, or C# you need an application server.

[guyafe]

Thanks,
Does that mean that (say) Glassfish can process JSP code?

Guy

[ditesh]

yes tomcat and glassfish can process jsp and servlets

[guyafe]

Tanks,
Now everything is starting to make sense