Since repositories host sensitive data and corporate IP, a typical organization's repository will be private and will require authentication before access is permitted.
Many organizations use a repository as a service (SaaS, multi-tenant). These are accessible on the Internet and are protected using authentication. A popular example is GitHub Team.
Many organizations will host their repositories in their private networks (i.e. behind a firewall). As a result, these repositories are not accessible over the Internet. Organizations can continue to use the SaaS Controller and still remotely access their private, behind the firewall repositories using an agent that is deployed in the organization's private network.