A freelance worker (or independant worker) is a single-person business. You are your own boss and you work for clients. Unlike regular employees, you control your work conditions: work hours, prices, etc...

Depending on your local laws, as a freelancer you will probably need to produce a business income report and you may consider some work related expenses in your net income calculation.

Here are a few useful links:

• Quebec : Sole Proprietorship (Self-Employment)
  https://www.educaloi.qc.ca/en/capsules/sole-proprietorship-self-employment
• Quebec : Am I a Self-Employed Worker ?
  https://www.educaloi.qc.ca/en/capsules/self-employed-workers
• Canada : Employee or Self-Employed?
  http://www.cra-arc.gc.ca/E/pub/tg/rc4110/rc4110-e.html
• Self employed individuals - choosing a year-end when starting your business.
  http://www.taxtips.ca/smallbusiness/choosingayearend.htm