Product life cycle
There is lots of different steps in a product life cycle these steps are the introduction the growth the maturity and the decline.
The introduction stage is the beginning of the product when the product has first been released for example when the Xbox one was first introduced nobody had heard of it and people wanted to see how good it was.
The growth process is after the product has been out for a while and people are just starting to buy it and the product is growing in the world this means that the companies are making more money.
Maturity is when it has reached as much sales as it can still lots of people are buying it but not as much as before as more and more people have already got the product.
The decline process is when the product has reached a all time low where there is very few amount of people that buy the product and the amount of sales will keep reducing until eventually sales are completely gone.
An extension strategy is a thing used to increase the market share for a given product or service and keep it in the maturity phase of the marketing product life cycle other than going into decline.