A bookcase is a piece of furniture consisting of horizontal shelves, usually placed on a wall or in a free space in a room. It is used to store a variety of items, from books and decorations to kitchenware and files. Shelves can come in a variety of sizes, styles and materials, from wood to metal. Their design can be open or closed, and the shelves can be fixed or adjustable, allowing the space to be adapted to different storage needs.