A corporate identity is the manner which a corporation, firm or business presents themselves to the public, such as customers and investors as well as employees. It is a primary task of the corporate communications department to maintain and build this identity to accord with and facilitate business objectives. It is typically visually manifested by way of branding and the use of trademarks but also includes things like product design, advertising, public relations and the like.
In general, this amounts to a corporate title, logo (logotype and/or logogram) and supporting devices commonly assembled within a set of guidelines. These guidelines govern how the identity is applied and would include approved colour palettes, typefaces, page layouts and other such.