Fork

A fork is a new version of a project that is started by a new team or by defecting team members. OSE encourages forks to occur as needed, because different stakeholders may have different needs than what the Main Trunk may offer. Before starting a fork, developers are encouraged to consider the Roadmap of a given project

See an example of Free Software forks of Linux (this shows mainly forks, but the distinction between forks and branches is not clear):