A photo frame is a decorative or functional object that holds and displays photographs, posters or artwork. It usually consists of a wooden, plastic or metal molding with an opening to hold the picture in place, often with glass or acrylic covering it for protection. The term can also refer to digital frames which are electronic devices designed to display images electronically using LCD screens. These types of photo frames allow users to change their displayed image by means of a memory card slot, USB port or built-in storage.