1/ iPhones and iPads have search — Just like Spotlight on Macs, in fact, but to some this remains a hidden feature: to launch Spotlight on an iOS device, swipe down on its screen – not from the very top of the screen; that displays Notification Center.
Start in the middle of the screen and swipe downwards – your finger should be moving downwards before it actually contacts the screen.
2/ Results from all over — Start typing in the text input field at the top, , and your iOS device will start showing you results, just as on OS X. As you continue typing, you’ll see the results change, as Spotlight zeroes in on what you’re looking for, showing you a number of different types of results, including your apps, words in emails, Calendar and Contacts, websites, Map locations and more.
But, oddly perhaps, you cannot search for files on iCloud Drive.
3/ iOS Spotlight is a launcher — Tap an app to launch it; tap a song to play it; tap any other item, such as a contact, email message, or web page, to open it in the appropriate app. Spotlight is great for launching an app that’s hidden in a folder somewhere on your iDevice.
4/ Searching the web — Spotlight can search for content on the Internet. It suggests matches from search terms among Wikipedia articles, news, content on the iTunes Store, App Store, and iBooks Store, as well as nearby places. These searches fall under the Spotlight Suggestions category. (For nearby places to work, you need to have Location Services turned on in the Privacy settings.) Spotlight Suggestions are available in New Zealand, and only 14 other countries.
5/ Specify the results you want — Choose which categories Spotlight displays when you search. Go to Settings>General> Spotlight Search and check or uncheck any of the categories you see. You can also change the order in which they display. To do this, tap and hold one of the rows and drag it up or down in the list.