Today, a human resources company called me and told me that the recruitment of employees in a bank belongs to the labor dispatch system.

Hello, my understanding is that outsourcing refers to an enterprise handing over a certain job to an external specialized company (such as the human resources company mentioned above), such as recruitment. External specialized human resources companies help enterprises recruit needed employees, which can be employees with large turnover, such as waiters and salesmen, or executives with scarce resources (such as senior headhunting companies).

Combined with your question, "human resources company" is to help "a bank" recruit employees. If it is labor dispatch, it means that your contract is signed with this human resources company, and you are managed by the human resources company, including your salary, benefits and vacation. According to the contract or agreement between the bank and the human resources company, the bank pays a certain management fee to the human resources company.