A cravat is a type of silk neckwear descended from scarves worn knotted at the neck of seventeenth century Croatian mercenaries enlisted in the French military. The word cravat derives from the French pronunciation of Hrvat, an individual of Croation heritage and ancestry. The cravat is the predecessor of the modern necktie.
In a business-casual or weekend wardrode, a cravat is an appropriate substitute for a necktie. A cravat adds a splash of color to an open-necked shirt and sublimely elevates an otherwise ordinary and mundane ensemble. Consider the photograph of Cary Grant from Alfred Hitchcock's 1955 classic To Catch a Thief. Grant's gray jacket and open-necked white shirt would appear lifeless without that splash of silk at his throat.
My source for handmade silk cravats is Beau Ties, Ltd. of Middlebury, Vermont.
If you elect to wear a cravat, be forewarned that you will receive the occassional comment regarding Thurston Howell, III. Do not be dissuaded. The person making the comment is probably wearing SpongeBob SquarePants underwear.