whether the authorized signatory of a contract is a legal person or an authorized person is generally signed by the legal representative. If the legal representative is unable to sign for some reason, a power of attorney can be issued and signed by the authorized person, which has the same legal effect as the signature of the legal representative. First, here, we should distinguish the meaning of "legal person" and "legal representative". Legal person generally refers to an institution or unit, for example, a company is a legal person; The legal representative generally refers to the principal responsible person of an institution or unit, such as the chairman of a company who is the legal representative of the company. Therefore, the "legal person" you mentioned in your question should be the "legal representative of the legal person". Second, in addition, it is necessary to distinguish the concepts of "authorized person", "authorized person", "agent" and "principal". Among these four words, the meaning of the grantor and the principal is similar, that is, the person who originally had the right and now exercises it by others; The meaning of the authorized person is similar to that of the agent, that is, the person who originally had no rights and now accepts the entrustment of others to temporarily exercise their rights; However, the agent and the principal are legal terms, while the authorizer and the authorized person are not legal terms. Therefore, the "authorizer" you refer to in your question should be the "agent", that is, the person who accepts the authorization. Third, generally speaking, when a contract is signed, the signature of one of the legal representatives or agents has legal effect; If two people sign at the same time, it is also legally binding.
According to the law, the types of agents in Article 163 of the Civil Code include entrusted agents and legal agents. The entrusted agent shall exercise the agency right as entrusted by the principal. The legal agent shall exercise the power of agency in accordance with the provisions of the law. Article 165 Where the power of attorney entrusts an agent to authorize in writing, the power of attorney shall specify the name of the agent, matters of agency, authority and time limit, and shall be signed or sealed by the principal. The above content is the relevant answer. Under normal circumstances, if we want to sign an authorization contract, it is usually signed by the legal representative, which is usually a power of attorney issued by the legal representative for some reason, and the final contract is signed by the authorized person.