Was the
word "transaction" actually used in the question? If so, then I will speculated that this was a leading question, and the interviewer wanted to discuss "transactions".
Transactions are optionally supported by both JMS and Databases (
JDBC), and the interviewer probably wanted you to discuss such support. Additionally, since two different systems that support transactions, was mentioned, the interview probably wanted you to discuss the concept of "two phase commit".
Henry