A more thorough explanation:

A legal code is a complete system of laws, rules, or regulations that are carefully arranged and officially promulgated. It is a compilation of existing statutes and much of the unwritten law on a subject, which is newly enacted as a complete system of law. A code is composed partly of such materials as might be at hand from all sources, such as statutes, cases, and customs, supplemented by such amendments, alterations, and additions as are deemed by the codifiers necessary to harmonize and perfect the existing system.

• The Uniform Commercial Code is a legal code that governs commercial transactions in the United States.
• The Code of Justinian is a legal code that was compiled by order of the Roman Emperor Justinian and first authoritatively published in A.D. 529. It contained 12 books and is one of four works that make up what is now called the Corpus Juris Civilis.

These examples illustrate how a legal code is a complete system of laws that are carefully arranged and officially promulgated. The Uniform Commercial Code governs commercial transactions in the United States, while the Code of Justinian is a legal code that was compiled by order of the Roman Emperor Justinian and first authoritatively published in A.D. 529.