Short novel, noveleta, novelette or nouvelle  is a narrative of less length than that of a novel, although without the economy of narrative resources typical of the story. Publishers and literary societies commonly describe the novella as a short story between 17,000 and 40,000 words.   
The antecedent of the short novel is the medieval short story.  Julio Cortázar defined it as a "genre halfway between the story and the novel". 
In Spanish, in its beginnings, the word novel began to be used in the Italian sense, novella, with the meaning of a shorter story than the romanzo, in French roman, equivalent to the current novel in Spanish. This is how Miguel de Cervantes used it in his Exemplary Novels, a compilation of short novels. For a longer narrative the term book was used.
However, over time the word novel came to designate all the stories longer than the story, for which it became necessary to distinguish between novel and short novel.
Short novel vs. novella
The term noveleta is a term used in magazines and in everyday life for decades,   although it is not included in the Dictionary of the Spanish language. There is also a tendency to consider the noveleta an even shorter type of novella,   placing it according to whose criterion between 7,500 and 15,000 words.
Examples of short novels
Examples of short novels are:
The metamorphosis of Franz Kafka
George Orwell's Farm Rebellion
The Old Man and the Sea by Ernest Hemingway
Pedro Páramo by Juan Rulfo
The Stranger by Albert Camus
The persecutor of Julio Cortázar
The Canterville Ghost by Oscar Wilde
Mario Vargas Llosa's puppies
The perjury of the snow by Adolfo Bioy Casares
William Faulkner's Bear
1922 by Stephen King
The well of Juan Carlos Onetti
Thomas Pynchon's Lot 49 Auction
The incredible and sad story of the candid Eréndira and her heartless grandmother by Gabriel García Márquez
The lawyer Vidriera by Miguel de Cervantes
Breakfast at Truman Capote's Tiffany's.