Vodafone Group plc is a global telecommunications company headquartered in the UK. It operates networks in over 30 countries and owns 45% of Verizon Wireless in the US. Vodafone has around 332 million subscribers worldwide, making it the world's largest mobile telecommunications company by revenue and second largest by subscribers. The company derives its name from "voice" and "data" services provided over mobile phones. It has a primary listing on the London Stock Exchange and is a constituent of the FTSE 100 index.