|Freelancer versus employee
The employee gets a contract according to his jobdescription and offered a monthly salary.
A freelancer is an expert in his domain (sales, HR, trainer, coach, finance, procurement etc). He gets in contact (most of the time) with a contracting firm who is organized like a temp working office but using freelancers.
This is a general flow, if it works well, you will have your project for 3-6-9-12 months or more depending.
DIFFERENCES: Commercial law