Novellas are generally described as short length novels.
According to the Science Fiction & Fantasy Writers of America, a novella has between 17500 to 40000 words. Anything above 40000 classifies as a novel and below 17500 is a short story. Just like salt, the novella is seldom referred by name but is ubiquitous throughout the literary world. Here some famous classics.
The Call of the Wild by Jack London
The Strange Case of Dr Jekyll and Mr Hyde by Robert Louis Stevenson
A Christmas Carol by Charles Dickens
The Time Machine by H.G Wells
Of Mice and Men by John Steinbeck
Shawshank Redemption by Stephen King
Although a bane for booksellers, novellas are making an inevitable resurgence. People used to pen letters but we now tweet our messages. Who reads novels anymore?