Unstage a file in Git

When you stage a file in Git, you instruct Git to track changes to the file in preparation for a commit. To disregard changes to a file, and not include it in your next commit, unstage the file.

Unstage a file

To remove files from staging, but keep your changes:
```
git reset HEAD <file>
```
To unstage the last three commits:
```
git reset HEAD^3
```
To unstage changes to a certain file from HEAD:
```
git reset <filename>
```

After you unstage the file, to revert the file back to the state it was in before the changes:

git checkout -- <file>

Remove a file

To remove a file from disk and repository, use git rm. To remove a directory, use the -r flag:
```
git rm '*.txt'
git rm -r <dirname>
```
To keep a file on disk but remove it from the repository (such as a file you want to add to .gitignore), use the rm command with the --cache flag:
```
git rm <filename> --cache
```