Silicon Valley is the southern part of the San Francisco Bay Area in Northern California in the United States. Geographically, the Silicon Valley encompasses all of the Santa Clara Valley including the city of San Jose, the southern Peninsula Valley, and the southern East Bay.
The region is home to many of the world's largest technology corporations as well as thousands of small startups.
The expression originally referred to the region's large number of silicon chip innovators and manufacturers, but eventually came to refer to all the high-tech businesses in the area.
It is now generally used as a metonym for the American high-tech sector. Despite the development of other high-tech economic centers throughout the United States and the world, Silicon Valley continues to be the leading center for high-tech innovation and development, accounting for one-third of all of the venture capital investment in the United States.