What is an ordinance?
An ordinance is a law created by a local government, such as a city council or county board of supervisors. Local governments can only create laws on matters that the state government says they can. Ordinances can cover a variety of topics, including things like zoning and rental building requirements.
You may see a collection of city ordinances referred to as a "municipal code" or "city code," or a collection of county ordinances referred to as a "county code." A code organizes the ordinances by topic, like ordinances related to fire safety.