There following are the labels/terms for the various ranges of word counts that I am going to be using for my fiction ebooks in the descriptions that I write up for my ebooks.
Micro-flash: up to 100 words
Flash fiction: 100 to 500 words
Short-short: 500 to 2,500 words
Short story: 2,500 to 7,500 words
Novelette: 7,500 to 17,500 words
Novella: 17,500 to 40,000 words
Novel: 40,000 to 110,000words
Epic: over 110,000 words
During my research, I also came across the term "drabble" which is for a fiction piece of exactly 100 words; I doubt that I would ever use it.