A query letter serves to sell your story or article to the editor.
Editors have hundreds of queries crossing their desks every day.
You may only get one chance to make your sell, that chance is your query letter. Having a professionally written query letter may be the difference between having your article published or rejected. A query letter must be professional and organized or it is likely to end up with an editor's reject stamp on it. A query must be free from spelling errors and typos. If you use the spell checker program in your word processor, print your letter out and carefully read through it.