To commit files:
  1. In the Project Explorer, select the file to commit. If you select a folder, project, or solution, any eligible child items will also be committed.
  2. Choose Source Control > Commit.
  3. The dialog will list the files that can be committed.
  4. In that dialog, you can deselect any files you don't want to commit and enter an optional comment.
  5. Click Commit.

Enabling the VCS > Options > Commit Immediately option will bypass the dialog and immediately commit the files without a comment.