the visual components that form part of the overall brand and are defined by guidelines that state specific fonts, colors, sizes, placement, and usage to ensure the identity is consistent in all its applications and thereby retains the visual integrity of the brand.
use it in real life: your identity is not your logo or your brand but it is a part of both. Lets use a famous brand, identity and logo as an example: Pepsi. The identity of Pepsi includes the logo, which is the circle symbol with the Pepsi word and its typeface, color, proportion of the word to the symbol, etc. as well as the way the logo looks and is used on all marketing components, products, signage, and anything visual that represents the business of Pepsi. Now lets make it personal: your “identity” is your personal name and the way you want your name to look everywhere your name could possibly go. Your name is not your personality, but it is a part of it and it does define some aspects of you. All aspects of you as a person are your “brand” and the symbol of your name is your “logo”.
See also: brand, logo