Expedia, Booking, hotels.com are online Travel agencies. OTA’s started their expansion with the advent of the internet by adding flights, rental cars, and vacation homes. Vacation homes started to appear on OTAS around 2013, OTAS are simply listing vacation homes in exchange for a commission to be paid by the owner of the house. OTAS do not verify homes that are offered for rentals, they simply share the written descriptions and photos that owners are sharing. Owners are also entering manually their daily rates on those websites.
Owners will most of the times post their properties on different websites and OTAS which may create some confusion if they are not very well organized by maintaining their availability calendar and pricing up to date. In case of an issue arising from a misrepresentation of what is on the website or problems with the owner while they arrive, renters will be on their own.