This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
I don't know. I do know that questions of the form "What is the difference between X and Y" are annoyingly vague and the answers are not likely to be helpful. Why don't you ask a question like "I want to do (insert your requirements here). Should I be using JTA or JTS or what?"