I am new to portal technology.
there are so many products available in the market like BEA weblogic portal,websphere portal,JBOSS portal and liferay Portal.
what are the diff. in this. and which one is better.
These are all major commercial portals which provide implementation of JSR 168 and JSR 286 specification, and provide additional features like social netwokring/integrated content management/ready to use portlets . JSR168/286 is the portlet specification , just similar to our familar servlet specification.
Liferay and JBOSS also provides community editions to download freely.
You need to consider cost and features while selecting the Portal provider. We have been using Websphere portal in most of our projects. Liferay is also considerable.