Marketing strategy and marketing mix are related elements of a comprehensive marketing plan. While marketing strategy is aligned with setting the direction of a company or product/service line, the marketing mix is majorly tactical in nature and is employed to carry out the overall marketing strategy. The 4P's of the marketing mix (Price, Product, Place and Promotion) represent the tools that marketers can leverage while defining their marketing strategy to create a marketing plan.
In corporate law and taxes, an affiliate is a company that is related to another company, usually by being in the position of a member or a subordinate role, a subsidiary. According to Investopedia, a subsidiary is a company "whose parent is a majority shareholder." (That means the parent owns 51 percent or more of the other company's shares of stock.