| An Electrician is a person who has skills in electrical wiring, hardware (transformers, switch gear, breaker panels, wire, conduit, to name a few), installation and maintenance of this hardware, and so on.
Typically an electrician at one time started as an apprentice electrician and worked underneath a supervisor or other sort of mentor for a time to learn the ins and outs of the business. They then study the National Electrical Code and local/state additions either in school or through independent study and take the required exams to become a journeyman electrician. Being licensed as a journeyman electrician is required by most electrical companies before they will hire you as a regular electrician and give you the responsibilities and the pay as such. Further study and more license exams and one can become a master journeyman electrician. Most firms place these master electricians as foremen on job sites and in lead roles as far as the responsibilities go.
Being a licensed electrician requires almost intimate knowledge with the electrical code, and the hows and whys of the business. One will probably spend a few years getting soaked with wire pulling lubricant as an assistant before he/she has the knowledge to take the required license tests.
The above pertains to electricians in the United States, other countries have their own electrical codes. | 
