According to Keller, brand knowledge is defined in terms of two components, brand awareness and brand image. Brand awareness is the consumers’ ability to identify the brand under different conditions and consists of brand recognition and brand recall.
Brand image is defined as perceptions about a brand as reflected by the brand associations held in consumer’s memory. Keller classified associations into three major categories: attributes, benefits, and attitudes. These associations can vary according to their favorability, strength, and uniqueness. Considering these aspects, a brand may have a positive customer based brand equity, when consumers are more accepting of a new brand extension, less sensitive to price increases and withdrawal of advertising support or more willing to seek the brand in a new distribution channel etc., which means they react favorably to marketing activity of the brand as compared to an unnamed or fictitiously named version of the product, or a negative customer based brand equity when consumers react less favorably to marketing activity for the brand in the same comparison context.