Horizontal integration is used through Disney because it helps to develop the company, increase the product differentiation, achieve economies of scale, reduce competition or access new markets.
Vertical integration is used through the business so that the company can gain control over their industries value chain. this also helps to gain control over its suppliers or distributors in order to increase the firms power.
HI is different from vertical integration, where a firm usually expands into another production stage rather than merging or acquiring the company in the same production stage. For example, a company is vertically integrating if it expands from manufacturing industry to retailing industry, while HI would mean buying other firms in the same manufacturing industry.