Uniform Laws are model statutes drafted by the Uniform Law Commission. The purpose of creating model laws is to promote consistency in state laws. Uniform Laws are not "law" in a state unless they are enacted by the state legislature.
Model Acts and Codes are drafted by various organizations. The American Bar Association publishes Model Acts, including the Model Business Corporation Act. The American Law Institute publishes Model Codes, including the Model Penal Code. Like the Uniform Laws, Model Acts and Codes are not "law" unless enacted by a state legislature.