This document summarizes the Boston Consulting Group (BCG) matrix, which is a tool used to analyze different business units within a company based on their market share and market growth. It divides businesses into four categories: Question Marks, Stars, Cash Cows, and Dogs. Question Marks have high growth but low market share. Stars have high growth and high market share. Cash Cows have low growth but high market share. Dogs have low growth and low market share. The matrix is used to determine how to allocate resources among business units.