A brand's visual identity is its characteristic appearance. A properly constructed visual identity will be consistent, comprehensive and compulsory.
In order for the visual identity to be consistent, its usual to have a brand book which is given to every department commissioning or producing visual materials, and to commissioned graphic designers. A set of templates is usually sent to all staff.
The brand book will consist of the main logo with rules on how to use it, the official typefaces, the palette of colours, instructions with examples on photography, and characteristic layouts for magazines, stationery and so on.
Brands usually fall into one or more category of being product brands, environment brands, behaviour brands and communication brands. For product brands, the visual identity book should set out examples of packaging along with specific rules on, for example, type face size or how colour is matched on a particular substrate. For environment brands, the visual identity should set out who decor is constructed, styles of furniture, lighting and signage. For behaviour brands, the visual identity should set out uniforms or dress codes. For communication brands, the visual identity should specify standard layouts for advertisements and print materials.
The visual identity's job is to clearly, credibly, and relevantly present the brand's distinctive promise. This will only be useful if all of the brand's visual communications conform to the visual identity. This requires clear policies to be communicated to all staff, associates and designers, and materials which do not match the brand to be rejected. Lack of brand discipline is the most common cause of brand failure.