With any electrical installation, there are electrical codes that must be followed. Outdoor electrical installations are no different. Because outdoor light fixtures may be exposed to all sorts of weather conditions, they are designed to seal out wind, rain, and snow. Most outdoor fixtures also have special protective covers to keep your light working in adverse conditions.
Receptacles that are used outdoors must have ground-fault circuit-interrupter, or GFCI, protection for safety. GFCI devices automatically trip if they sense an imbalance in the circuit that may indicate a fault to ground, which can occur when electrical equipment or anyone using it is in contact with water. GFCI receptacles are used in wet locations, including bathrooms, basements, kitchens, garages, and, of course, outdoors.
Here’s a list of the specific requirements for outdoor lighting and outlets and the circuits that feed them.
Source: The Spruce