Git cherry-pick

https://git-scm.com/docs/git-cherry-pick
https://www.kernel.org/pub/software/scm/git/docs/git-cherry-pick.html

Real-life usage example:

https://community.openvpn.net/openvpn/wiki/CodeRepositories:

Release branches do not have any active development and only bug fixes are typically applied to these branches after the release. A new release branch is created for each major release (2.x). All bug fixes should be developed against the master branch, and where it is decided to include such fixes in a minor release (2.1.x, 2.2.x, etc), it will be cherry-picked from the master branch and into the suitable release branches.

Git rebase

https://www.kernel.org/pub/software/scm/git/docs/git-rebase.html

Real-life usage example:
https://community.openvpn.net/openvpn/wiki/CodeRepositories:
"Developers being granted a feature branch must ensure that their branch is regularly ​rebased against the master branch."