Open the first app
Swipe up slightly from the bottom to show the Dock
Touch and hold the second app in the Dock
Drag the second app to the left or right edge of the screen
Release it when the screen splits
Adjust the divider bar to change each app’s size
To close Split View, drag the divider all the way to one side
To use Slide Over, drag the second app to the center of the screen instead of the edge
To switch apps in Split View, swipe up and choose a different app from the Dock
To use multitasking, make sure Settings > Home Screen & Multitasking > Multitasking is enabled