Identity – a set of graphical forms and principles for building a visual communication company, united by one idea. The main 1-st task of this set is to allocate the company among the competitors of the market segment where it works or is just about to announce itself. The second task is to create and consolidate a recognizable image among consumers, clearly connected with the company itself and its name (in the case of a well-known company with its Brand).
Naming, Logo, Corporate Identity and Brand Book are, without a doubt, parts of the Identity.
On the link you can see a detailed definition of what it is and what it is eaten with.