A reporter is typically on the pay roll of a particular newspaper while a freelance journalist is a journalist who specializes in a particular field and works independently by contributing articles to various newspapers and magazines.
Reporters normally cover a specific beat like crime, health, education, civic matters, etc. The chief reporter who is in charge of city reporting allocates reporters their beats. Reporters interpret the events they are reporting on, in terms of their significance or what they mean to people. However, making a living as a freelance writer is quite a difficult proposition unless of course you are a celebrity or a specialist in a particular field.
Freelancers often work as stringers or as retainers for newspapers and magazines. You can increase the scope of your work by writing promotional pieces for small local businesses. A successful freelancer is one who can tap the demand in the marketplace, is a skilled negotiator and a master of time management.
A reporter usually has a background in journalism in terms of either a diploma or a degree. A freelance journalist, on the other hand, requires good writing skills and sufficient knowledge of the things s/he is writing about.