Many people here use third party websites to purchase travel. I thought you might be interested to know who owns who.....
The first travel group of companies is the Expedia Group. This company has two divisions. The first includes:
Expedia
Hotels.com
Trivago
Orbitz
Travelocity
Hotwire
Cheap tickets
Ebookers
VRBO
Carrentals.com
HomeAway.com
The second comes under the TripAdvisor banner. These include:
TripAdvisor
SeatGuru
Airfarewatchdog
Viator
Cruisecritic
Citymaps
SmarterTraveler
There are more subsidiaries but I just posted the ones I've seen on this board.
The next group of travel companies is Bookings Holdings. This includes:
Booking.com
Priceline
Agoda
Kayak
Cheap Flights
Rentalcars.com
Momondo
Open Table
Both of these holding companies are publicly traded in case you want to buy stock in them.