Before talking about brand audit it is important to point out brand and brand equity concepts.
Brand – refers to a set of elements that make a product, a company, an organization, person etc. to be recognizable and different. A brand has got tow dimensions: one generated by features (what it actually is) and one generated by the way they are perceived by the audience (how is it perceived).
A brand means money – a measurable power to promote sales.
Brand equity – refers to the positive influence that a brand has on sale. It is defined as the difference of price paid for a known product to a lesser known one.