what is nfpa 72 is it code or standard ?
A code is a law, regulation, ordinance. or code that establishes requirements for construction and fire safety.
A system standard is a document that the codes refer to that details the application, installation, location, performance. And maintenance of that which is required in certain places by the code.
A product standard is a listing agency standard that ensures product safety, reliability, and certain performance levels.
The difference between a code and a standard is that a code tells you what you need to do, and a standard tells you how to do it. For example, a code may say that a building must have a fire alarm system. The standard will spell out what kind of system and how it must work.
the three different components ( building and life safety codes, system standards like NFPA 72, and product standards ) are balanced to work together. If one changes, then one or more of the remaining two must change to keep the system balanced.

NFPA 72 reflects the input of many industry stakeholders whose interest is in creating the highest standards possible to help ensure the proper functioning of fire alarm and signaling systems.
NFPA 72 covers :
- the application. installation. location. Performance .inspection . testing. And maintenance of fire alarm systems.
- supervising station alarm systems.
- Public emergency alarm reporting systems.
- fire warning equipment.
- Emergency communications systems (ECS).
The Code is organized into chapters, each relating to a different topic and several annexes that contain supplemental information. The contents are organized into four main categories