Substantial changes to the range of offerings or the markets served or both are known as:

This is known as 'Diversification'

A business is said to ''diversify'', if they launch a slight different or a completely new product to cater to either cater to their current consumers or to target a new demographic market.

This is one of the best ways that a company can improve their revenue, acquire new customers, and lower their dependence on a few products.