1, production basis, the defender is entrusted by the criminal suspect or defendant or appointed by the court according to law, and the agent ad litem is entrusted by the parties and their legal representatives;
2, litigation status, the defender has an independent litigation status, but the agent does not;
3. Object: Defenders for criminal suspects and defendants, and agents for private prosecutors, victims and parties involved in incidental civil litigation.
legal ground
Article 58 of the Civil Procedure Law of People's Republic of China (PRC)
The parties and legal representatives may entrust one or two persons as agents ad litem. The following persons may be entrusted as agents ad litem: (1) lawyers and grassroots legal service workers; (2) Close relatives or staff members of the parties concerned; (three) citizens recommended by the community, units and relevant social groups where the parties are located.
Article 35 of the Criminal Procedure Law
The responsibility of a defender is to provide materials and opinions on whether a criminal suspect or defendant is innocent, light or relieved of criminal responsibility according to facts and laws, and to safeguard the litigation rights and other legitimate rights and interests of the criminal suspect or defendant.