If you run git stash, all of the changes to tracked files on the working tree
will be put into a commit-like entity in the stash list.
If you want to be a bit choosier about what gets saved during a stash, you can
include the --patch flag.
With --patch, you can interactively select hunks from the diff between HEAD and the working tree to be stashed.
$ git stash --patchOnce in the interactive mode initiated by --patch, you'll be presented with a
change of changes and some options. You hit y for "yes, include this" and n
for "no, don't include that". And then there are some more advanced options
which you can read about in the Interactive Mode section of git-add's man
page.
See man git-stash for more details.