Incognito mode is a feature available on web browsers that allows users to browse the internet without saving any data about their browsing session. This includes browsing history, cookies, and other data that websites may use to track user activity. On an iPhone, incognito mode is also known as Private Browsing and is available on Safari and Google Chrome.

Here are the steps to turn on Private Browsing on Safari for iPhone:

1. Open Safari on your iPhone.
2. Tap the Tabs button.
3. Swipe to the Private tab group button, then tap the tab that you want to open.
4. For additional privacy, you can choose to lock Private Browsing when youre not using it. When you lock your device, your private tabs in Safari will also lock. Then, when you unlock your device again, just unlock Private Browsing with Touch ID, Face ID, or your device passcode.

Here are the steps to turn on Incognito mode on Google Chrome for iPhone:

1. Open Google Chrome on your iPhone.
2. Tap the More icon and select New Incognito Tab.
3. A new Incognito tab will open, and you can start browsing.
4. To close the Incognito tab, tap the X icon on the top left corner of the tab.

Its important to note that while Private Browsing or Incognito mode can help protect your privacy by not saving your browsing history, it does not make you completely anonymous online. Your internet service provider and the websites you visit can still see your activity.