According to Wikipedia:
Freelancer is a global crowdsourcing marketplace website, which allows potential employers to post jobs that freelancers can then bid to complete. Founded in 2009, its headquarters is located in Sydney, Australia, though it also has offices in Southern California, Vancouver, London, Buenos Aires, Manila, and Jakarta.https://en.wikipedia.org/wiki/Freelancer.com
This platform is probably one of the largest in the world in its field, having a wide variety of professionals and services.
It works in two ways, the first is for the employer to upload a brief description of what they need, the profile of the freelancer they are looking for and their budget. Then the freelancer makes a proposal and can also see the proposals of other people.
The second one is that the professionals develop a good profile and upload a bit of their work or portfolio, then the client decides with what freelancer he wants to negotiate.
As it is a global platform, you must verify in which financial currency the work is being negotiated to avoid misunderstandings.
It has a section called Showcase, which works as an exhibition of the work done by those who advertise on this website and how much work costs. You can share it on social networks or like it.
It is a great alternative for those who do not know how to start and learn from other professionals. You can visit his website here.