You can own repositories individually, or you can share ownership of repositories with other people in an organization.
You can restrict who has access to a repository by choosing the repository's visibility. For more information, see "About repository visibility."
For user-owned repositories, you can give other people collaborator access so that they can collaborate on your project. If a repository is owned by an organization, you can give organization members access permissions to collaborate on your repository. For more information, see "Permission levels for a user account repository" and "Repository permission levels for an organization."
With GitHub Free for user accounts and organizations, you can work with unlimited collaborators on unlimited public repositories with a full feature set, or unlimited private repositories with a limited feature set. To get advanced tooling for private repositories, you can upgrade to GitHub Pro, GitHub Team, or GitHub Enterprise Cloud. For more information, see "GitHub's products."
You can collaborate on your project with others using your repository's issues, pull requests, and project boards.
Repositories and individual files are subject to size limits. For more information, see "What is my disk quota?"