This report delves into the core functions of marketing, using Marks and Spencer (M&S) as a primary case study. It explores the key roles and responsibilities of marketing, including branding, product management, customer service, and promotion, and their interrelationships with other organizational departments such as R&D, Finance, HR, and Operations. The report analyzes the marketing environment and how marketing functions relate to the wider organizational context. Furthermore, it compares the marketing mix strategies (focusing on the 7Ps) of M&S and Tesco, evaluating how these organizations apply the marketing mix to marketing planning to achieve business objectives. A basic marketing plan is produced and evaluated. The report emphasizes the significance of interdepartmental relationships in achieving business objectives, providing a comprehensive overview of marketing strategies and their practical application in a competitive retail environment.