Public relations involves managing information between an organization and the public to earn goodwill. It aims to persuade stakeholders like the general public, employees, media, government and others. There are two types of public relations - internal relations with shareholders, employees and suppliers, and external relations with consumers, community and media. Sales promotion provides incentives to stimulate immediate sales and attract new customers, holding current customers and countering competition. It includes techniques like free samples, bonuses, and trade-in promotions for consumers as well as price reductions and free products for business-to-business customers.