You can manage the users and permissions for a team project by using team project groups. A team project group is a collection of users and associated permissions within a specific team project. You can create any number of groups for your project, and grant them whatever project-specific permissions you want the group's members to possess. You can also use the default groups created with a team project.
A project-level group provides permissions only for that project. This type of group does not provide permissions for users in related components, such as SharePoint Products and SQL Server Reporting Services. To add a user to a team project, you might need to add that user to groups in those products also. For more information, see Add Users to Team Projects.
Some team project groups are defined when your project is first created. In addition, all default collection-level groups are added to the project. However, you must manually add any custom collection-level groups you might have created, if appropriate to do so. Any membership changes you make to collection-level groups as part of the team project will be effective for all projects to which that group is assigned. Any permissions changes, however, are specific to the current team project, whether the changes are to project-level groups or collection-level groups.