I read the post: how-do-i-revert-all-local-changes-in-git-managed-project-to-previous-state, which is a very good post / answer, so plus 1's all around.
I understand all the commands that are mentioned, except this one:
git revert ...
What do the dots mean? - I am sure the answers are on the web, but the search engines seem to ignore punctuation, so I get hundreds of pages of basic git revert with no other mentions of "...".
The three dots are meant as a placeholder (meaning that you should replace the three dots with an actual argument). They are used as an ellipsis (which is confusing, as ... also has special meaning as a range operator for Git).
The manual page may be helpful:
$ man git-revert
NAME
git-revert - Revert some existing commits
SYNOPSIS
git revert [--[no-]edit] [-n] [-m parent-number] [-s] [-S[<keyid>]] <commit>...
So git revert expects a <commit> argument (without the angle brackets). The three dots here indicate that you can also pass more than one <commit> argument.