Facebook, Google, Apple, Tesla, airbnb, Uber, twitter, Dropbox: all of these highly successful companies have started as innovative start-ups and all come from Silicon Valley. Why does this small region in California create such a high density of innovative business concepts? The answer to this question lies in the contextual consideration of start-ups and their entrepreneurs. They do not operate in a vacuum, but in interaction with their environment. Thus, the high density of innovative and scalable start-ups in Silicon Valley can be explained by the successfully established local Entrepreneurial Ecosystem. An Entrepreneurial Ecosystem is a spatially limited region which, through the work of networked independent actors and regional resources, offers a supportive environment for entrepreneurship and thus provides favourable conditions for the development of start-ups.