NOTE: This deserializeUser will throw an error until we set up the DB in the next step so comment out the whole block and just call done(null, null) in the function deserializeUser. Submit your page when you think you’ve got it right.
My confusion has been solved. I realized that (‘users’) is a collection name, as many replies to this thread mentioned already, that perhaps will be defined somewhere later in the ''Advanced Node and Express" challenge.
I was originally confused by the fact that, without even having it defined, the challenge went straight into .findOne (a search method). Usually, programs would define the collection first, before conducting .findOne method, perhaps somewhere in later challenge we’ll see ('users) being specifically defined and actually being loaded with user data.
(Otherwise it wouldn’t make sense to conduct database search without defining it)