I’m planning to study Java EE but I do not know where to start.
Based on Java EE version history there are technologies present in lower versions which are not available in the higher version. Do I need to learn J2EE 1.4 before learning Java EE 5 or 6? Or is it better to learn the latest version since their purpose of doing it is to improve the previous version.
Can you also suggest some resources on Java EE?
Unless there is a direct need to work on a legacy system, it is perfectly fine to start with the newest version of the Java EE standard.
For starters I’d recommend free tutorials by Marty Hall, especially Configuring & Using Apache Tomcat to get you up and running.
There is also an official Java EE beginners tutorial, The Java EE 7 Tutorial. It is decently written and contains a lot of examples. By the end of it, you should have a pretty good idea where to go next.