Adoption Curve
Adoption curves are an illustration of the stages in which the adoption of a technological innovation grows in a market.
When something new comes into the market, whether it is a new model of car or an entirely new technological tool/concept, it is not adopted all at once. At first, only a few people give it a try before it gets to the masses.
Take cell phones as an example: as use cases for cell phones grew, the support network for them also grew. As they began to be adopted by more people, each generation of adopters paved the way for the next one to make the technology better.
This process of adoption can be observed across a range of markets where different sectors of a market come on board with a new product or technology at different stages and for different reasons.