Many organisations produce more than one product.  The product mix is the complete range of items made by the organisation.  For example, Procter and Gamble produce Bold, Daz, Pampers, Hugo Boss, Wash & Go, Oil of Ulay, Sunny Delight and many others.

A firm will often keep launching products from its mix, so that the launch a new product will coincide will the decline of an existing one.  This is shown in the diagram below.

Further Reading

Heinz - The Product Mix