This document discusses brand extension, including its history, types, advantages, disadvantages, and impact on brand equity. It traces brand extension back to the 1960s and notes it involves using an established brand name to enter new product categories. Brand extensions can be classified as horizontal (line/category extensions) or vertical. The advantages include reduced costs and risk from leveraging brand recognition, while disadvantages include potential damage to the parent brand's image if poorly executed. The document analyzes how brand extensions can affect various elements of Aaker's brand equity model, including brand awareness, loyalty, and perceived quality. Managing these elements carefully is important for the success of any brand extension efforts.