A query letter is a formal letter sent by a writer to magazine editors, literary agents and sometimes publishing houses or companies, to propose writing ideas.[1]
For example, a standard requested format for a manuscript query letter to a literary agent could be approximately 200–400 words, expressing the following information:
The literary agent would then decide whether to contact the author and request to see the manuscript, based on the contents of the query letter. In this sense, the query letter is an author's first step toward getting their manuscript published.