This document provides an overview of the Boston Consulting Group (BCG) Matrix, developed in the 1970s. The BCG Matrix classifies businesses into four categories based on their relative market share and the market growth rate: Stars (high share, high growth), Cash Cows (high share, low growth), Question Marks (low share, high growth), and Dogs (low share, low growth). It is a tool used to assess the cash flow of products/businesses and help with resource allocation and divestment decisions. While simple, the BCG Matrix has limitations as it only considers two factors and high share does not always mean profits. It remains, however, one of the most famous and simple portfolio planning tools used