Electrical wiring in general refers to insulated conductors used to carry electricity, and associated devices. Materials for wiring interior electrical systems in buildings vary depending on:
Intended use and amount of power demand on the circuit
Type of occupancy and size of the building
National and local regulations
Environment in which the wiring must operate.
Electrical wire must be up to code in your specific area, and codes change from country to country, state to state, even county to county and city to city. Be sure to check your local regulations and guidelines before you get to work.