Holding page for Online Travel Agencies or OTA’s (also called Online Travel Aggregators or Hotel Price Aggregator – HPA).
The key difference between an Online Travel Agency and a hotel comparison website, is that you can actually use the OTA to book your travel (they have their own booking engine) which will take care of flights and accommodation. Generally, a hotel comparison website will utilise one of the OTAs engines (see TripAdvisor). Another example is Kayak which uses the hotels.com booking engine
The 2 most notable are Expedia and Priceline, because between them they own most of the hotel comparison websites that you will find yourself on, including wotif, travelocity, trivago, orbitz, booking.com and agoda.
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