Some enterprises will pay a certain amount of living expenses.
Some enterprises will practice with half pay.
Some enterprises will not pay any salary before internship during the training period.
Some companies will deduct a certain amount of deposit every month during the internship period, but they will return it to you in full after they formally join the company.
This is to ensure that you can think that the breach of contract during the training period will cause the training cost loss to the enterprise during the training period.