What is the difference between 'reset hard head' and 'reset hard'?

Question

I am new to git, so question might be very easy, that what is the difference between git reset --hard HEAD and git reset --hard?

Answer 1

HEAD is implied when you do not specify that argument.

However, you could do e.g. git reset --hard HEAD^ to nuke the commit at HEAD, i.e. undo it in a way that rewrites history.