Freelancing sites are the sites where contractors post jobs and freelancer apply for the jobs. The contractors can hire workers, where as freelancers can make money by working on the jobs posted by the contractors. One of the most trusted freelancer sites is upwork. On upwork you can find jobs on variety of niches. Another good site for freelancers is fiverr. On fiver you can create a gig to sell your products and services and you make money by selling your gigs.