I summarize the following criterias:
Committed = Stored in .git directory.
Modified = Changed since checked out, but not in the staging area.
Staged = Modified and put into the staging area.
Tracked = ???
Untracked = ???
But I don't know how to decide a file as tracked or untracked. I guess there must be some kind of tracked file collection to search for. Though it seems so natural that a newly created file is considered by Git as untracked.
Thanks.