You're both right.

The resin glands (also called trichomes) are the THC containing structures on the outside of your buds. When bud is really strong, it's frosty with resin glands. And yes, they do make hashish out of this.

Resin is also a term used to refer to that sticky black residue in your bowl. It is primarily tar, but has plenty of THC. It most certainly is smokeable, but we prefer to wait till we're desperate.

So you see, everyone is correct, and I am high as a motherfucker. Good day.