A stock photograph is a digital file someone can purchase for their own use. Stock photographs can be sold in two ways, as Royalty-Free or Rights Managed. Royalty free allows the buyer to use the photo in anyway they wish for however long as they wish. They cannot resell the file or prints but can use it in brochures, flyers, mailers, websites...so on. Rights-Managed files only allow the buyer to use the photo for a particular project, the artist would determine the terms and pricing on a per project basis.