What's the difference between the different types of boards out there?

  Clients Jobs Agency
Interaction with Clients You interaction is with clients directly, organization does little/no communication with clients You interact with employers directly, organization does little/no communication with clients Organization handles clients and just gives you work. You have little/no interaction with clients
Control over working environment Generally you can work however, using own tools, supplies, set own hours, etc Employer controls how you work generally. Provides tools, sets hours, tasks, etc. Agency might direct you on what tasks to do but you have flexibility on how to accomplish them
Payment Client pays you, but through the organization (which may takes its cut) Employer pays you salary (withholding taxes) Agency pays you
Choice of Client or Project Complete control of client/project Complete control of job selection Little/no choice of project or client
Vetting/Interviews Clients vets you Companies vet you Organization vets you, Client wouldn’t really vet you individually