The Boston Consulting Group (BCG) Matrix is a strategic tool used by businesses to evaluate their product lines or business units. It categorizes them into four quadrants based on market growth and market share: Stars, Question Marks, Cash Cows, and Dogs. This helps companies allocate resources effectively and identify which products to invest in or divest. In the BCG Matrix, Stars represent high-growth, high-market-share products that require investment to maintain their position. Cash Cows are low-growth, high-market-share products that generate steady revenue. Question Marks are high-growth, low-market-share products needing strategic decisions, while Dogs are low-growth, low-market-share products that may be candidates for divestiture.