Legal analysis: The client signs and writes his or her name on the entrustment contract (agreement). For example, Zhang San entrusts Li Si to attend a meeting. Zhang San is the client and Li Si is the trustee. The power of attorney is signed. Want Zhang San. A principal refers to a person who entrusts others to handle matters for him/her. In the securities brokerage business, the principal refers to a natural person or legal person who can buy and sell securities in accordance with national laws and regulations.

Legal basis: Article 919 of the "People's Republic of China and Civil Code" An entrustment contract is a contract in which the client and the trustee agree that the trustee will handle the client's affairs.