While it's easy enough to ask websites not to track your browsing activity in Safari, they do not have to honor your request. Plus, some of the third-party content providers that websites use can actually invasively track you across other websites. Thankfully, iOS 11 includes a way to minimize companies from tracking you across the web on your iPhone.
Apple's default browser for iOS, Safari, has a ton of useful features, and there's so many that it's impossible to know everything you can do to browse the web more efficiently. One you may not know about brings the Command + F keyboard shortcut right to your mobile browser so you can search for words or phrases directly on any webpage you're viewing.
Having websites coded for mobile browsing is great for small screens, but if you have a Plus model iPhone or even the iPhone X, desktop versions of websites might show you more of what you want. Plus, there's the case of poorly designed mobile websites, where the desktop view is clearly the better option with more functionality and features. Luckily, asking for desktop sites in Safari is simple.