WHAT IS THE IPHONE'S DEFAULT SEARCH ENGINE?

For some reason mine changed. I don't know what happened. I want the default one but I've tried changing it to yahoo, google and bing but none of them look familiar/similar to my old one. I have the latest version of IOS and i have an iPhone 4S. I've never changed it before please tell me which one.

Safari

I'm pretty sure the default search engine is google but the homepage is apple.com