Swipe from the left edge of the screen to the right to go back in many apps
Tap the Back button in the top-left corner if it appears
Use the Back link in the top-left corner in Safari and some apps
Press the Home button if your iPhone has one to return to the Home Screen
Swipe up from the bottom edge on Face ID iPhones to go Home
Swipe up and pause, then choose the previous app from the app switcher if needed
Use the AssistiveTouch menu if Back is difficult to use
Press the side button to wake the screen if you only need to exit sleep mode