The Git working tree is comprised of files in their present state as they exist on the file system. The Git index -- to which files are staged -- is the second dimension. A commit of the staged files ...

For example, you can split a file into smaller chunks with a customized suffix and a specific number of lines per file. The following command demonstrates this combination: split -l 4 -d -a 4 ...

The Git index, along with the need to use the "git add" command before performing a commit, is often a source of confusion for beginners. These "git add" examples will make things clear.