Can you explain the Boston matrix to me?

The Boston matrix is a model used by companies to display their product portfolio. The Boston matrix is split into four ways of classifying products. First there are stars these are products which have high market share in a fast growing market.  Next there are problem children also known as question marks. These are products with a low market share in a market with high growth. Then there are cash cows these are products with high market share in a low growth market. Lastly there are dogs, dogs have a low market share in a market with low if any growth, these products are often removed from a product portfolio because they can be costly to maintain. The Boston matrix allows businesses to consider what each product needs in terms of marketing strategies or product development. It must be considered that the Boston matrix is closely linked with the product life cycle.