Hi faisal, not sure how this is a Servlets question, and not sure which forum would this
thread be more appropriate in.
However,
you should consider Synchronization as a way to keep one call to a method being run at one time. Meaning no other caller can call that method while the first caller is running.
This is different than transactions, which is database related, and basically states that one or more sql statements can run and either they all commit or they all rollback. So while one user has a transaction occuring, another can also have their own transaction running, and all concurrency issues are handled by the database.
With this in mind, I am just going to close this thread, and if you have more questions, please try to post them in the appropriate forum. Each forum has a topic, and posts in each forum should be about the topic.
Thanks
Mark