Apple's Siri, Search (formerly known as Spotlight) and Spotlight on the Mac, have long used Bing. But Apple is ditching the search engine from Microsoft in favor of Google's.
So for example, when users ask Siri for which she needs to visit the web (either by asking her a question she doesn't know the answer to or by asking her to search the web directly), the results users get will be from Google, not anymore from Bing.
"Switching to Google as the web search provider for Siri, Search within iOS and Spotlight on Mac will allow these services to have a consistent web search experience with the default in Safari," said Apple in its statement. "We have strong relationships with Google and Microsoft and remain committed to delivering the best user experience possible."
Apple's motivation for switching from Bing to Google is because iOS and Mac are already using Google Search as their default provider.
Google has been sending Apple $3 billion a year for search traffic, and Google itself has made a bunch of money from iOS. It was reported that the figures appeared to even exceed the amount of money that Google had made from Android.
A Microsoft spokesperson provided the following comment when asked about Apple switching from Bing to Google on iOS:
The changes include regular web links as well as video results. Initially, web image results will still come from Bing before Apple gradually switch it to Google.
Search results that users will see in different cases will come directly from the search API. What this means, users will be getting raw ranked search results that start below all of the ads and Knowledge Graph that usually appear on regular Google home page.
It's worth noting that when a result is showing videos from YouTube, users are still going to see ads. So here Google is still getting revenue, while not directly.
All searches and results are encrypted and anonymized so they cannot be attributed to any individual user. But once users tap/click on the 'Show Google results' link, obviously, Google's standard tracking method will apply.
Tapping or clicking directly on a website result will take users straight there, not through Google.
iPhone users in China will continue to get results from Chinese search engine Baidu. Bing is still used for image search.