Freelancing is a type of self-employment. Instead of being employed by a company, freelancers tend to work as self-employed, delivering their services on a contract or project basis.
An example of a freelancing job
An example of a freelancer would be an independent journalist who reports on stories of their own choosing and then sells their work to the highest bidder. 
Skills are required for freelancing: Communication skills, others, problem-solving, applying initiative and IT skills