Stock photos are professional photographs that are bought and sold on a royalty-free basis and can be used for limited purposes. It is a cost-effective method for designers, commercial advertisers and marketing organizations to obtain professional quality photos and images without the costs of hiring a full-time professional photographer. The stock photographer or distributor retains ownership of the images and the purchaser acquires limited usage rights set by the Terms of Service Agreement. Terms of Service policies differ among stock photography distributors and should be read carefully. Stock photos can be purchased through a subscription and downloaded from a stock photography distributor’s web sites.