A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation: all other movements are prevented, including translation and tilting. Hinges may be made of metal, wood, or other materials, and may be either external or internal to the objects they connect.
A hinge joint is a joint in the body that is formed by the meeting of two or more bones that are connected by a hinge-like joint, such as the elbow or knee.
In bookbinding, a hinge is a thin strip of flexible material (usually cloth, paper, or leather) that is glued to the inside covers at the spine. The hinge allows the cover to flex during opening and closing, and helps to keep the spine from cracking.
Hinges are also used in publishing to mean the place where two leaves of a book are connected. The term is used both for the physical construction of the book (the stitching or other method used to hold the pages together) and for the editorial decision of where to break the text.
A common use for hinges is in doors, where they allow the door to be opened and closed. A less common use is in books, where hinges allow the book to be opened and closed without damaging the spine.
The purpose of a hinge is to allow two objects to rotate relative to each other about a fixed axis. Hinges are generally designed to be concealed, so as not to mar the appearance of the two objects.
Hinge is an important part of the book publishing process because it allows authors to connect with readers and build a relationship with them. This is essential for any author who wants to sell their books and build a career in publishing.