Positions are a cornerstone of projects on Crowdsourcer.io. They’re what brings together contributors and projects.
As a contributor you could do a search for project with free spaces for a C# developer, for example, and once you’ve found a project that interests you, you could send in an application to join it. As you complete tasks in a position your approval will hopefully increase. Then, should you apply to the same position in any other projects, project creators will be able to see your rating which should improve your chances of being accepted.
Likewise, as a project creator, you can set some project positions based off of what skills you need for your project to grow, and hopefully receive applications from people offering to help out. Read about creating positions here: Project Positions
Crowdsourcer.io is built on trust. You should always review any applications you receive before accepting users into a project. See: Before accepting applications.