Uber Technologies Inc. is an American multinational online transportation network company headquartered in San Francisco, California. It develops, markets and operates the Uber mobile "app", which allows consumers with smartphones to submit a trip request, which the software program then automatically sends to the Uber driver nearest to the consumer, alerting the driver to the location of the customer. Uber drivers use their own personal cars. As of August 2016, the service was available in over 66 countries and 507 cities worldwide. The Uber app automatically calculates the fare and transfers the payment to the driver. Since Uber's launch, several other companies have replicated its business model, a trend that has come to be referred to as "Uberification".
The legality of Uber has been challenged by governments and taxi companies, who allege that its use of drivers who are not licensed to drive taxicabs is unsafe and illegal; some taxi driver unions have called Uber drivers "pirate taxis".