title: JPA difference between transaction isolation and entity locking
body: <p>I have read about transaction isolation levels. It is used to prevent parallel transaction executions errors. Its quite obvious.
  There are also locking modes available for entities. I understand how they work.</p>
  
  <p>But I cant find the reason why I need locking? I have used transaction isolation levels already. Why  do I have to use locking?
  Do isolation levels and locking make the same job?</p>