What is Silicon Valley and why is it so important worldwide?

Slicon Valley, the entrepreneurial and technological city of the United States, located in the Santa Clara Valley in California. It is a region that since the 80s has become the most important technological place in the world.

Between the cities of San Francisco and San José are the headquarters of giant companies such as Google, HP, Apple, universities such as Stanford, and offices full of entrepreneurs, executives of technology firms and venture capital executives.