The NEC is divided into an  introduction and nine chapters.

Chapter 1: General includes :

• definitions of terms used throughout the Code
• the general conditions that apply to all installations.

Chapter 2 : Wiring and Protection covers the general requirements for :

• branch circuits
• feeders
• services
• load calculations
• overcurrent protection
• grounding and bonding of equipment and systems.

Chapter 3 : Wiring Methods and Materials covers

• wiring methods
• the methods for installing conductors
• the conductors

Chapter4 : Equipment for General Use covers equipment

• flexible cords
• switches
• receptacles
• panelboards and switchboards
• luminaires
• appliances
• motors
• air conditioning and heating equipment
• transformers
• generators
• phase converters

Chapter5 :Special Occupancies

• installations in hospitals
• the significant restrictions on wiring methods for use in hazardous.
• mobile homes.
• recreational vehicle parks
• marinas.

Chapter 6: Special Equipment provides special rules

• signs
• luminaires
• welders
• swimming pools
• computer rooms
• X-ray equipment
• industrial machinery
• fire pumps
• solar photovoltaic systems.

Chapter7 : Special Conditions Covers :

• emergency and other types of standby systems
• energy storage and stand- alone systems.
• fire alarm systems.

Chapter8 : Communications Systems

stands apart from the rest of the NEC and can be used alone except in those cases where it is a requirement of Chapter 8 that some other part of the NEC be applied.

Chapter 9 :Tables

includes reference tables that contain information that can be used to satisfy requirements throughout  the NEC.