There are a lot of websites out there claiming to be able to find you the best deals on airfare. But did you know that many of those sites are powered by the same search engine?

It’s called ITA Matrix, and it’s a powerful software that’s behind sites like Orbitz and Kayak.

Wise Bread explains why you may never have heard of this search engine before:

Unlike other flight search websites, ITA Matrix does not book flights for you. Other websites earn money through bookings, while ITA earns money through selling its software to the travel industry. This is why consumers are not likely to see their ads or find them by googling “book cheap flights.” What ITA Matrix does is search for flights so you can book them elsewhere.

ITA Matrix will show you flight options by price, then you can go to the website and book there directly. You can also choose to book through a travel agent or another website, depending what your cheapest option is.

The site also has a lot of other great perks for people who have airline miles to use, travelers who have flexible dates and flexible airports, and more.

Be sure to check out this little “secret” the next time you’re booking a trip!