Fire is general slang for very good cannabis, or anything good. "That's fire" carries no specific information about aroma, potency or growing.
In practice
Fire is the most common word in reviews and social posts, which makes it the least useful. A smoke report that says "fire" has told you that the reviewer liked it. Useful reports describe the aroma when broken and ground, the flavour on the first and later draws, smoothness, ash and burn, how the cure smells, and reported effects, plus how it was grown and stored. On GenetixBay, a smoke report is most useful when it is tied to a journal and a batch record, so readers can see what grow and cure produced the flower being called fire.
Don't confuse with
- Fire as a fault: harsh, hot, coughing smoke, usually from poor drying or curing or a dirty pipe, is the opposite of the slang meaning.