In brief
git stash stores selected local changes so the working tree can be used for another task. Untracked files are not included by default as they are with explicit --include-untracked.
Useful to know
git stash stores selected local changes so the working tree can be used for another task. Untracked files are not included by default as they are with explicit --include-untracked. [1]
Inspect what was stored before relying on it. apply and pop differ in what happens to the saved entry. Restoring can conflict, so a stash does not promise effortless transfer onto any changed base.
Sources
For further detail and to check the information: