If you have a very important change in a branch, but that branch is not merged yet, you can use cherry picking.
You use that if you want to work with that change, but instead of merging that branch, you cherry-pick that commit with the important change.
git cherry-pick <commit hash>
For more details, refer to:
https://www.previousnext.com.au/blog/intro-cherry-picking-git
You usually avoid cherry picking. You do this only in exceptions.