Booking Holdings is the world's largest online travel agency (OTA), operating five brands — Booking.com, Priceline, Agoda, KAYAK, and OpenTable — with Booking.com driving the vast majority of revenue. Booking.com offers over 4.4 million accommodation properties across 220+ countries, plus flights, rental cars, and attractions. Priceline focuses on discount travel in North America, Agoda serves Asia-Pacific, KAYAK is a metasearch engine that earns referral fees by directing users to other travel platforms, and OpenTable connects diners with restaurants while selling reservation management software to restaurant operators. Booking Holdings earns revenue through two models: an agency model, where Booking.com earns a commission from hotels when a stay is completed, and a merchant model, where Booking.com collects payment upfront from the traveler and pays the supplier later, earning the spread plus payment processing fees. The merchant model now accounts for roughly 70% of gross bookings and enables incremental fintech revenue. The key financial drivers are room nights booked, average daily rates, take rates, and the share of bookings coming through direct channels rather than paid search. Direct bookings, which account for roughly two-thirds of Booking.com's room nights, carry no acquisition cost and come from more loyal, higher-frequency travelers. Booking Holdings is pursuing a multi-year "Connected Trip" strategy to expand into a full-trip platform covering flights, hotels, cars, attractions, and dining, supported by its Genius loyalty program and AI-powered tools including natural language search and customer service automation.