There is no definitive answer to this question as every kindergarten classroom is different and every teacher has their own definition of what nonfiction is. However, in general, nonfiction for kindergarten is any text that is true and factual. This could be a book about animals, plants, buildings, transportation, geography, history, etc. Basically, anything that is not made up or imaginary could be considered nonfiction.
Here are some examples of books that could be considered nonfiction for kindergarten:
-"Animalia" by Graeme Base
-"The Watertower" by Gary Crew
-"The Story of Buildings" by G. Brian Karas
-"The Way Things Work" by David Macaulay