The BCG matrix is a chart developed by the Boston Consulting Group in 1968 to analyze a company's business units and allocate resources. It categorizes products as cash cows, dogs, question marks or stars based on their relative market share and market growth rate. Cash cows are profitable but mature, dogs have low market share in a mature industry, question marks consume cash but could grow, and stars have high share in a fast-growing market. The matrix aims to help companies decide which units to fund or sell off. It has been criticized for oversimplifying and potentially misguiding resource allocation decisions.